It's very funny to me that the reason the tablet was rebooting in the first place was something in the over the air update failing, which prevented him getting the patch which, in turn, allowed the exploit which gave him root. A more thorough investigation into what was failing auto updates would have saved him a bunch of money. My guess, as he mentioned he is using it for an information display, the software he's using puts on device policies to stop the device locking, etc. It's probably attempting to use a unsupported method to try and suppress updates which the OTA updater takes an update failure and reboots the tablet to get it to revert to the previous working version.

But Cyber people gotta Cyber I guess.