Alright. Guess it depends on the psychiatrist though. If he ends up getting released after a few years of 'psychiatric care' after the whole thing blows over he's pretty much off the hook. Can't do anymore *covert operations*, though.
ed: As a matter of fact I don't think it's common practice to not just plain lock up or execute criminal psychopaths.
IIRC, such cases are under a careful observation even after being released (assuming that they are), not to mention he would be thrown out of the army. And social stigma connected with being mentally ill is quite significant.
Remember we're most likely talking PTSD here. Some people just can't handle the stress of the war, and this occasionally shows like that.
Also, it should be investigated how the heck did he get so far unsupervised, with a gun and ammo. A soldier under arms can't just walk away from his/her post, especially not alone. It seems that somebody screwed up, badly. And no, this wouldn't be a conspiracy of any kind, that would be way too obvious, too suspicious. Why was he able to leave his post? And if he didn't left his post, how did he sneak out carrying a weapon? Why was he alone (I don't think soldiers would split up and leave him alone for any reason)? These questions have to be answered, and I suspect a gross display of incompetence. Anyway, we need more data on this incident, and the government should provide it, or it might end badly.