HELP! Dead and Don't Know Why!...

I have a 2006 Tundra Limited 4x4 that I bought new. When my son got his license last year I gave it to him and bought me a new one. A couple weeks ago the water pump began to leak. He thought he could easily change this and tore into it going further than necessary pulling radiator etc. He soon found out that this vehicle is timing chain driven and wasn't comfortable anymore. He put that back together, put the radiator and loose parts in the back and had it towed (backwards) to a small shop. They called the next day stating the truck won't start!... Here we are. My son leaves for the Air Force in less than a week, needs his truck, and the shop can't figure out what's wrong. When they turn the key on, most of the dash lights come on. It will turn over but won't start, no headlights, the OBDII port is dead.
Q: Could there be an issue with towing it backwards on our VERY rough highway roads to the shop? Is there a way to check for tripped inertia type sensors? Has anyone ever experienced anything like this and/or has an idea where to begin to fix this time sensitive issue?
Thanks
Kevin USAF (Ret)

 

Did he remove the timing belt and put it back together?

 

Literally so many things he could have done. Very vague, I think at this point I would take it to a good shop.