It's sounds questionable to me as well...I'd definitely wait at least two weeks before offering again. If it was a regurge, the wait will help to heal the esophagus (snake stomach acid is some strong stuff) and if it wasn't a regurge, the wait won't hurt either.

In the future if you think it might be a regurge and want to make sure, take a photo and/or baggy it up and take it to the vet. My boa did regurge once after we had her for about a month and the full recommended regime for recovering after a regurge is wait 4 weeks, then feed very, very small, and work your way back up slowly with prey. You don't want to get the snake in a regurgle cycle, which young snakes can do if they are stressed and had a regurge.