I think this guy's actions are reflective something that TPI has discussed a lot: Complacency.
He was complacent. He knew he was in command of the situation, and acted that way - then found out he stuck his head into the nest of a 10 pound brown recluse spiders who was actually very polite, and really didn't want to kill anyone...
Then he shit a brick because his worldview just got rocked like a Cro-Cop shin kick to the melon with the realization "Oh My G0D I fucked up..."