I have checked the logs and the log doesn’t apparently register the issue. Here is what the most recent 502 kicked in the log:
2013/08/01 06:13:34 [notice] 4979#0: signal 17 (SIGCHLD) received 2013/08/01 06:13:34 [notice] 4979#0: worker process 15418 exited with code 0 2013/08/01 06:13:34 [notice] 4979#0: signal 29 (SIGIO) received
I disabled every other WP plug-in to eliminate potential conflicts and the 502 still occurs. Also, the form writes to the DB and functions in every other way normally. The 502 only occurs when attempting to edit the form.