Did she actually consume it fully then regurge? I know we had one incident with our Nelson's Milksnake where she was about 80% done swallowing when something spooked her. She just sort of spat it back out and went off to hide (had this happen once too when I accidentally bumped into a BP tub hard and the snake spat back the almost swallowed rat and dashed off to her hide). Could this have happened?