Once again, it absolutely is enough as long as the superiors do what they are supposed to do. In this case they didn't and there is certainly a very reasonable argument that Paterno should have followed up to make sure they did, not necessarily from a legal standpoint, but from a moral one.
As I have said, I think Paterno probably did what a lot of people would have done when faced with doing something that he knew would destroy the life of a lifelong friend. He reported it and allowed someone else to do the dirty work, and when they told him they looked into it and didn't find a basis for a criminal charge he was probably relieved and just accepted it.
To me the real negative against Paterno will be if it is proven he knew of prior acts of sexual contact with a child before 2002, and not just that Sandusky took a shower in the same community lockerroom shower that a boy did. Again, I'm not saying even that is right, but that alone is not proof of sexual assault or even sexual contact of any kind.