Honestly It could be the first time he got in an oh shit moment. Doesn't matter how much you train bad shit can happen when the juices are flowing for real. Whats really scary is the back up was a good 5-7 minutes out.
Not saying he shouldn't see a shrink and I am not saying he shouldn't have left that shit out of his report. He should have to go to mandatory counseling. He should get reprimanded for omitting it from the report. He should consider if he cant work through this finding a new career.
Again though I have had soldiers that we trained constantly that still freezes or panicked the first time real lead was coming at them.