Tell ansible to keep the remote script and then use use python -m trace to walk through it ...
ANSIBLE_KEEP_REMOTE_FILES=1 ansible-playbook -vvvv
# grab the remote filename ansible creates
# ssh to the remote host
python -m trace --trace <module-file-path>
Example:
$ python -m trace --trace /home/jtanner/.ansible/tmp/ansible-1387469069.32-4132751518012/command 2>&1 | head
--- modulename: command, funcname: <module>
command(21): import sys
command(22): import datetime
command(23): import traceback
command(24): import re
command(25): import shlex
--- modulename: shlex, funcname: <module>
shlex.py(2): """A lexical analyzer class for simple shell-like syntaxes."""
shlex.py(10): import os.path
shlex.py(11): import sys