IMO I think it's related to the fight or flight. They can eat a prey size larger than them, and in the wild they probably due. I think if the prey immobilizes them, and they need to run; they will regurg.

I still don't handle my bp's after they eat due to safety, and I've never seen a regurg. Just because we can do something, doesn't mean we should. And, for the sake of inexperienced handlers I hope they continue to push "not to handle until 48 hrs of digestion."

Also, wait until he uses the potty. See how much energy he had to properly digest it.