NightLad,
I would say that he will be fine. I pull aspen out of their mouth all the time, especially if feeding F/T, as the aspen seems to stick to the rats better. As long as he is flicking his tongue, and you can see no blood, it just probably got stuck. Without a hand, it makes it difficult for them to remove it. It probably would have just got swallowed with his next meal, and ejected via the normal route for waste.