I see one way to reproduce something very close (if not same) as this bug (based on stack traces). I've used older PS 5.5.36 started like this: 

[openxs@centos p5.5]$ bin/mysqld_safe --no-defaults --log-bin --binlog-format=ROW --socket=/tmp/p55.sock --port=3355 &

to generate binary log and then replayed it on 5.6.21-70 to get a crash:

[openxs@centos p5.5]$ bin/mysql --no-defaults --socket=/tmp/p55.sock test
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.5.36-34.0-log Source distribution

Copyright (c) 2009-2014 Percona LLC and/or its affiliates
Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show master status;
+-------------------+----------+--------------+------------------+
| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+-------------------+----------+--------------+------------------+
| centos-bin.000015 |      107 |              |                  |
+-------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

mysql> drop table if exists ttt;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> create table ttt (
    ->   c1 char(250),
    ->   c2 time not null
    -> ) engine=myisam;
Query OK, 0 rows affected (0.05 sec)

mysql> insert into ttt(c1) values (1000*rand()), (1000*rand()), (1000*rand()), (1000*rand());
Query OK, 4 rows affected, 1 warning (0.00 sec)
Records: 4  Duplicates: 0  Warnings: 1

mysql> show warnings;
+---------+------+-----------------------------------------+
| Level   | Code | Message                                 |
+---------+------+-----------------------------------------+
| Warning | 1364 | Field 'c2' doesn't have a default value |
+---------+------+-----------------------------------------+
1 row in set (0.00 sec)

mysql> insert into ttt(c1) select 1000*rand() from ttt t1, ttt t2, ttt t3;
Query OK, 64 rows affected, 1 warning (0.01 sec)
Records: 64  Duplicates: 0  Warnings: 1

mysql> delete from ttt order by rand();
Query OK, 68 rows affected (0.01 sec)

mysql> flush logs;
Query OK, 0 rows affected (0.05 sec)

mysql> show master status;
+-------------------+----------+--------------+------------------+
| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+-------------------+----------+--------------+------------------+
| centos-bin.000016 |      107 |              |                  |
+-------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

mysql> exit
Bye
[openxs@centos p5.5]$ mysqlbinlog data/centos-bin.000015 | mysql -uroot test
ERROR 2013 (HY000) at line 66: Lost connection to MySQL server during query
[openxs@centos p5.5]$ su
Password:
[root@centos p5.5]# tail -120 /var/log/mysqld.log
CONFIG: use_epoll=1
CONFIG: readsize=0
CONFIG: conn_per_thread=1024(default)
CONFIG: for_write=0(default)
CONFIG: plain_secret=(default)
CONFIG: timeout=300
CONFIG: listen_backlog=32768
CONFIG: host=(default)
CONFIG: port=9998
CONFIG: sndbuf=0
CONFIG: rcvbuf=0
[Warning] handlersocket: open_files_limit is too small.
handlersocket: not listening for writes
handlersocket: initialized
2014-11-07 18:42:37 27489 [Note] Server hostname (bind-address): '*'; port: 3306
2014-11-07 18:42:37 27489 [Note] IPv6 is available.
2014-11-07 18:42:37 27489 [Note]   - '::' resolves to '::';
2014-11-07 18:42:37 27489 [Note] Server socket created on IP: '::'.
2014-11-07 18:42:37 27489 [Note] Event Scheduler: Loaded 0 events
2014-11-07 18:42:37 27489 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.6.21-70.0'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  Percona Server (GPL), Release 70.0, Revision 688
16:54:26 UTC - mysqld got signal 11 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
We will try our best to scrape up some info that will hopefully help
diagnose the problem, but since we have already crashed,
something is definitely wrong and this may fail.
Please help us make Percona Server better by reporting any
bugs at http://bugs.percona.com/

key_buffer_size=8388608
read_buffer_size=131072
max_used_connections=1
max_threads=153
thread_count=1
connection_count=1
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 69184 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x1eeb030
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 7f0a44b99d40 thread_stack 0x40000
/usr/sbin/mysqld(my_print_stacktrace+0x2c)[0x8be13c]
/usr/sbin/mysqld(handle_fatal_signal+0x461)[0x6512a1]
/lib64/libpthread.so.0(+0xf710)[0x7f0a75a20710]
/usr/sbin/mysqld(_Z10unpack_rowPK14Relay_log_infoP5TABLEjPKhPK9st_bitmapPS5_PmS5_+0x228)[0x8765f8]
/usr/sbin/mysqld(_ZN20Write_rows_log_event9write_rowEPK14Relay_log_infob+0xac)[0x859c1c]
/usr/sbin/mysqld(_ZN20Write_rows_log_event11do_exec_rowEPK14Relay_log_info+0x19)[0x859f99]
/usr/sbin/mysqld(_ZN14Rows_log_event12do_apply_rowEPK14Relay_log_info+0x26)[0x84a776]
/usr/sbin/mysqld(_ZN14Rows_log_event14do_apply_eventEPK14Relay_log_info+0x45e)[0x857eae]
/usr/sbin/mysqld(_ZN9Log_event11apply_eventEP14Relay_log_info+0x61)[0x851991]
/usr/sbin/mysqld(_Z29mysql_client_binlog_statementP3THD+0x1aa)[0x874c8a]
/usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0x3c25)[0x6d2d85]
/usr/sbin/mysqld(_Z11mysql_parseP3THDPcjP12Parser_state+0x5c8)[0x6d61c8]
/usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0xfb7)[0x6d78e7]
/usr/sbin/mysqld(_Z24do_handle_one_connectionP3THD+0x162)[0x6a5822]
/usr/sbin/mysqld(handle_one_connection+0x40)[0x6a5910]
/usr/sbin/mysqld(pfs_spawn_thread+0x143)[0xac8973]
/lib64/libpthread.so.0(+0x79d1)[0x7f0a75a189d1]
/lib64/libc.so.6(clone+0x6d)[0x7f0a741329dd]

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (7f0a24005780): is an invalid pointer
Connection ID (thread ID): 7
Status: NOT_KILLED

You may download the Percona Server operations manual by visiting
http://www.percona.com/software/percona-server/. You may find information
in the manual which will help you identify the cause of the crash.
141107 18:54:26 mysqld_safe Number of processes running now: 0
141107 18:54:26 mysqld_safe mysqld restarted
2014-11-07 18:54:27 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2014-11-07 18:54:27 27577 [Note] Plugin 'FEDERATED' is disabled.
2014-11-07 18:54:27 27577 [Note] InnoDB: Using atomics to ref count buffer pool pages
2014-11-07 18:54:27 27577 [Note] InnoDB: The InnoDB memory heap is disabled
2014-11-07 18:54:27 27577 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2014-11-07 18:54:27 27577 [Note] InnoDB: Memory barrier is not used
2014-11-07 18:54:27 27577 [Note] InnoDB: Compressed tables use zlib 1.2.3
2014-11-07 18:54:27 27577 [Note] InnoDB: Using Linux native AIO
2014-11-07 18:54:27 27577 [Note] InnoDB: Not using CPU crc32 instructions
2014-11-07 18:54:27 27577 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2014-11-07 18:54:27 27577 [Note] InnoDB: Completed initialization of buffer pool
2014-11-07 18:54:27 27577 [Note] InnoDB: Highest supported file format is Barracuda.
2014-11-07 18:54:27 27577 [Note] InnoDB: The log sequence numbers 2684184 and 2684184 in ibdata files do not match the log sequence number 2684204 in the ib_logfiles!
2014-11-07 18:54:27 27577 [Note] InnoDB: Database was not shutdown normally!
2014-11-07 18:54:27 27577 [Note] InnoDB: Starting crash recovery.
2014-11-07 18:54:27 27577 [Note] InnoDB: Reading tablespace information from the .ibd files...
2014-11-07 18:54:27 27577 [Note] InnoDB: Restoring possible half-written data pages
2014-11-07 18:54:27 27577 [Note] InnoDB: from the doublewrite buffer...
2014-11-07 18:54:27 27577 [Note] InnoDB: 128 rollback segment(s) are active.
2014-11-07 18:54:27 27577 [Note] InnoDB: Waiting for purge to start
2014-11-07 18:54:27 27577 [Note] InnoDB:  Percona XtraDB (http://www.percona.com) 5.6.21-70.0 started; log sequence number 2684204
CONFIG: num_threads=16
CONFIG: nonblocking=1(default)
CONFIG: use_epoll=1
CONFIG: readsize=0
CONFIG: conn_per_thread=1024(default)
CONFIG: for_write=0(default)
CONFIG: plain_secret=(default)
CONFIG: timeout=300
CONFIG: listen_backlog=32768
CONFIG: host=(default)
CONFIG: port=9998
CONFIG: sndbuf=0
CONFIG: rcvbuf=0
[Warning] handlersocket: open_files_limit is too small.
handlersocket: not listening for writes
handlersocket: initialized
2014-11-07 18:54:27 27577 [Note] Server hostname (bind-address): '*'; port: 3306
2014-11-07 18:54:27 27577 [Note] IPv6 is available.
2014-11-07 18:54:27 27577 [Note]   - '::' resolves to '::';
2014-11-07 18:54:27 27577 [Note] Server socket created on IP: '::'.
2014-11-07 18:54:28 27577 [Note] Event Scheduler: Loaded 0 events
2014-11-07 18:54:28 27577 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.6.21-70.0'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  Percona Server (GPL), Release 70.0, Revision 688
[root@centos p5.5]#

So, this is what to run to generate events on 5.5 that, while replicated to 5.6.21 or replayed there, cause similar/same crash:

drop table if exists ttt;
create table ttt (
  c1 char(250),
  c2 time not null
) engine=myisam;
insert into ttt(c1) values (1000*rand()), (1000*rand()), (1000*rand()), (1000*rand());
show warnings;
insert into ttt(c1) select 1000*rand() from ttt t1, ttt t2, ttt t3;
delete from ttt order by rand();

Side note: version 5.6.21 just does not allow to insert row directly without explicit value for c2 column:

mysql> select version(), @@sql_mode;
+-------------+--------------------------------------------+
| version()   | @@sql_mode                                 |
+-------------+--------------------------------------------+
| 5.6.21-70.0 | STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION |
+-------------+--------------------------------------------+
1 row in set (0.00 sec)

mysql> show create table ttt\G
*************************** 1. row ***************************
       Table: ttt
Create Table: CREATE TABLE `ttt` (
  `c1` char(250) DEFAULT NULL,
  `c2` time NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
1 row in set (0.00 sec)

mysql> insert into ttt(c1) values(1000*rand());
ERROR 1364 (HY000): Field 'c2' doesn't have a default value

but it seems it can get some via row-based binary log from older version:

[openxs@centos p5.5]$ bin/mysql --no-defaults --socket=/tmp/p55.sock test
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.5.36-34.0-log Source distribution

Copyright (c) 2009-2014 Percona LLC and/or its affiliates
Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show master status;
+-------------------+----------+--------------+------------------+
| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+-------------------+----------+--------------+------------------+
| centos-bin.000016 |      107 |              |                  |
+-------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

mysql> insert into ttt(c1) values(1000*rand());
Query OK, 1 row affected, 1 warning (0.01 sec)

mysql> show warnings;
+---------+------+-----------------------------------------+
| Level   | Code | Message                                 |
+---------+------+-----------------------------------------+
| Warning | 1364 | Field 'c2' doesn't have a default value |
+---------+------+-----------------------------------------+
1 row in set (0.00 sec)

mysql> select * from ttt;
+--------------------+----------+
| c1                 | c2       |
+--------------------+----------+
| 495.53474830047674 | 00:00:00 |
+--------------------+----------+
1 row in set (0.03 sec)

mysql> flush logs;
Query OK, 0 rows affected (0.06 sec)

mysql> exit
Bye
[openxs@centos p5.5]$ mysqlbinlog --verbose --base64-output=DECODE-ROWS data/centos-bin.000016
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!40019 SET @@session.max_insert_delayed_threads=0*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
DELIMITER /*!*/;
# at 4
#141107 18:54:06 server id 1  end_log_pos 107   Start: binlog v 4, server v 5.5.36-34.0-log created 141107 18:54:06
# at 107
#141107 19:08:29 server id 1  end_log_pos 175   Query   thread_id=6     exec_time=0     error_code=0
SET TIMESTAMP=1415380109/*!*/;
SET @@session.pseudo_thread_id=6/*!*/;
SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
SET @@session.sql_mode=0/*!*/;
SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
/*!\C utf8 *//*!*/;
SET @@session.character_set_client=33,@@session.collation_connection=33,@@session.collation_server=8/*!*/;
SET @@session.lc_time_names=0/*!*/;
SET @@session.collation_database=DEFAULT/*!*/;
BEGIN
/*!*/;
# at 175
#141107 19:08:29 server id 1  end_log_pos 220   Table_map: `test`.`ttt` mapped to number 44
# at 220
#141107 19:08:29 server id 1  end_log_pos 272   Write_rows: table id 44 flags: STMT_END_F
### INSERT INTO `test`.`ttt`
### SET
###   @1='495.53474830047674'
###   @2='00:00:00'
# at 272
#141107 19:08:29 server id 1  end_log_pos 341   Query   thread_id=6     exec_time=0     error_code=0
SET TIMESTAMP=1415380109/*!*/;
COMMIT
/*!*/;
# at 341
#141107 19:08:54 server id 1  end_log_pos 385   Rotate to centos-bin.000017  pos: 4
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;

Replaying the same binary log that crashed 5.6.21 on older 5.6 versions does not crash them:

[openxs@centos p5.6]$ mysqlbinlog ../p5.5/data/centos-bin.000015 | bin/mysql --socket=/tmp/p56.sock -uroot test
[openxs@centos p5.6]$ bin/mysql --socket=/tmp/p56.sock -uroot test              Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.6.11-log Source distribution

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> select * from ttt;
Empty set (0.00 sec)

mysql> show create table ttt\G
*************************** 1. row ***************************
       Table: ttt
Create Table: CREATE TABLE `ttt` (
  `c1` char(250) DEFAULT NULL,
  `c2` time NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
1 row in set (0.00 sec)

This is yet another reason for me to think it's a regression bug and test case is related to the problem all users here hit (even if their table definitions are different).