If 24 hours has passed it is a regurgitation.

Spitting it back out would have been immediately after feeding.

Now there are possible caused

1# Improper thawing of the feeder
2# Stress
3# Temps too low not allowing the animal to digest properly
4# Internal parasites

YOUR job is to figure out what could possibly be the cause, and to make sure not to feed this BP again for at least 2 weeks.

If it happens a 3rd time and 1 through 3 have been ruled out take your BP to a vet and have a fecal done.