Is it allocating any memory at that point? One reason for it to allocate memory is if you're using sprite dicing, etc on the sprite. You don't want to do that on animators unless you can handle the overhead. Also, is it REALLY the animator, and not the garbage collector, etc underneath it?
I can't say I've seen 1 or 2 sprites causing issues like that. Try the tile map demo, there are LOADS of coins there.