ok it was 2 weeks if I'm reading this correctly. how long from eating until regurging? If the rodent wasn't all the way down when it came back up is a lot different from being in the stomach and throwing it up.
there's many reasons why this can happen, some already stated, snake could be sick and not showing signs yet, the rodent is too big, stress and I sure there's more. with the information given, you're only going to get guesses, find a good exotic vet.