Tying up the CPU for too long could be plausible, but I'd be surprised if this was happening.
I've run both cameras for several days now with no crash by simply sleeping for 30 seconds after shutter actuation. Since the loop above seems pretty innocuous, it would appear that CPU hogging is a likely suspect. I've not tried to worsen the problem as I'm documenting an ongoing construction project and I need the cams working (apparently, I have a workaround at this point.) I can experiment when construction is finished.
It might be crappy real-time coding on Canon's part: Start timer, move something, check timer and abort if too much time has passed as a non-atomic operation.
