A few things could have happened.
First, you could've had white dust on the bottom of the post.
Second, that is a long time to leave it in the pot; I don't usually boil my toys for more then 7 minutes; five minutes ensures sterility. I doubt that it could have gotten hot enough to degrade the material, though.
Thirdly, however, if you left it in the pot without attending it, it could have gotten stuck to the bottom of the pot leading to some degradation of the material.
Either way, I'm sure it's not going to cause any problems with use.