And to have the bad guy quite literally sitting on top of you. I cannot imagine the mental fortitude it takes to maintain your composure to keep perfectly still and silent in that situation.
Right! I did think it was interesting that he said this adrenaline rush made it difficult to keep from laughing. It seems completely inappropriate, but makes sense at the same time. "Really, this is happening to me right now?"
Laughing can be a nervous or awkward reaction as well as the usual. I don't know if this is universal but I and others sometimes get a compulsion to laugh when told bad news.
You've got systems or exceptions buried deep in you to help in those kinds of circumstances, IMO. For example, my sense of claustrophobia almost completely vanishes when I'm getting really cold.