hmm, this isn't a problem I've heard a lot about, so it's probably an isolated fault, as opposed to a problem with all Touch's.
It's possible that your friend broke the screen, if I were you, I would contact Apple to see what they say. If it comes back and it turns out it was accidental damage, confront your friend!
On the other hand, it might not bother you that much, it's up to you!