There is always a chance something like this could happen. I stopped using rubber tipped tongs for this exact reason. They come off too easy. Definitely keep a close eye on him because its not the same as them passing an undigested worm. This is much harder and has the potential to cause problems. Its similar to them eating a small stick and could cause a blockage.

Now that doesn't mean you should panic, but if he becomes backed up you may want to get and oral laxative from a Vet. As Herpguy said though don't stress him if it is not necessary.