Lets wait before jumping on Joe
First of all remember Paterno got the information second hand. We don't know what he said to GA. Maybe he told the GA to report it to the police and he would report it to the Penn State authorities, which he did. Maybe the Penn State people came back to him and said that they turned it over to the police or that they had investigated and found nothing. Remember they are being charged with lying.
If someone came to you and and said they witnessed someone committing a crime would you, with no other evidence, go to the police yourself or would you tell him/her to go to the police. Paterno's son thinks that Joe knew nothing of the earlier allegation.
My take is that the GA should have gone to the police, as should the janitor in the earlier case. Neither did.
SoCal