If the teacher didn't like that kind of touching, she needs to teach him what he should do, not run it right up the chain of command as if it is a real grown-up dangerous situation.
Four year old are learing the difference between right and wrong and they can learn good touches and bad touches and appropriate ways to show affection.
Of course, we don't know the whole story. Could he really have been lewd and making remarks imitating the things he's seen on TV? Possibly. But then he needs to be taught the right things to do.
Was this a chronic thing with this kid? Who taught him this behavior? Big brother? TV? Movies? Mom?
I know for the two situations I described, things were innocuous enough, and that's good enough for me. It was never a problem.
Susan L.G.