I would wait at least two weeks before feeding him again. I couldn't really speculate on what caused it. Warming a rodent past a certain point causes gasses in the digestive tract to expand, which could cause the rupture you described. But I don't think I've heard of that causing a regurge.

How are his temps? Some colubrids are very sensitive and if their enclosure is too warm or too cool, they might have to reject a meal already eaten.