Stress, sure, but I'm thinking handling was the culprit in this case. Even light handling can cause a bp to regurgitate if it has eaten within 48 hours. Don't completely stress out about it. Just make sure his tank is set up perfectly for him. Two snug identical hides (assuming you are using a tank), and add some fake plants for good measure. Crumpled newspaper is just as easy, but fake plants look a little better in a tank. For a baby bp, I don't even bother trying to just put him in the tub anymore, I add crumpled newspaper right away. Babies are pretty finicky and insecure. For me personally, I only wait one week after bringing a bp home to feed it, but I also don't touch the bp, or even open the tub for that entire week unless absolutely necessary.

Good luck!