[Solved]
For anyone researching, the discovery was the temporary worker node account and the instantiation of MatLab. It wasn't a parsing difficulty.
Once we added a
run_as_owner = true
to the configuration and applied the appropriate configurations, the job successfully completes.
Many of these permission issues become more undocumented as desktop OS's move to Windows 7 and even more so in Win 8. UAC and other headwinds will likely prove to be increasingly difficult
to detect.