Zack, think like a small boa for a moment. He's gone through a change in his existance that he cannot even begin to understand. Then there's been changes even in that enclosure with your removing things that he may have just been starting to get used to. Then there's your buddies who sound like they probably scared the beejesus out of him with that knocking and overhandling.

Really Zack, what would you expect an animal as instinctive as a snake to do? He's become defensive - not aggressive in my mind - and it's going to be up to you to take the time and show the patience to help him calm down again. You are also going to have to decide that this snake deserves better than a crew of your buds doing that sort of thing to him in the future.

For now I would take this snake back to day 1. Double check your setup to make sure that's all good as far as temps, humidity, security, peace and quiet. Btw what is his feeding routine like as far as frequency and type/size of prey?

Move his enclosure if you need to, to a quiet place - cover his tank with a dark thin cloth if you need to help him feel secure again. Get into a routine of handling him even for 2 minutes. Be calm, be smooth in your movements and confident - not grabby or hyper, just firm but gentle. Get a grip on him and just hold him for a few moments then return him to his enclosure when he isn't fighting you. The point isn't to keep him out for long or give him free movement right now. It's just to get him used to removal and return to his home without stress. It could take weeks or months to get him calm enough to be able to stay out with you for any reasonable amount of time. With any snake it's about patience and baby steps.

He was calm, he became stressed - it's up to you to review what's occurred over your ownership of him and make the necessary adjustments to minimize that stress.