Never ever leave live prey in with a snake for that long. If mine haven't snatched it up with in 30 min it's taken out. All that did was stress the snake out way way more than it should have been. That's a very bad thing to get into. Prey will start to feed on the snake and the snake could be seriously injured. To the point of death. In this case you had a pup in there that's probably the only reason the snake isn't seriously injured, or chewed in a bit at the least. Since he is a new acquire he's probably highly stressed and I'm sure he will do a few refusals. Be hands off, make sure his husbandry is spot on, and when you offer his next prey make sure it's appropriately sized. You can try live but dont leave it in with him. Offer food 1x weekly. Don't try and feed too often. Goal here is to leave him alone and let him destress.