1. Okay, I think trying to kill the leadership of his unit is a big deal.
2. He may not have had access to plans.
3. Who says he didn't give away information!?
I agree it's a very big deal, but it sounds like something done on the spur of the momement. Right now, if he's guilty, it's either an act of sabotage, or a "crime of passion" (I hate that term, but that seems most appropriate), i.e. he got pissed over something, or got scared of going into combat and it got to him.
He could have given away info, but I'd be willing to bet money that if their camp is fully of local contractors, the place is crawling with spies.