You intentionally left out the other part of that quote - “With the benefit of hindsight, I wish I had done more.”
Sorry, that’s not an admission of guilt - simply a classy thing to say.
That statement is an admission he knew or should have known.
Joe Pa never said he had no clue as to what Sandusky was doing. If he didn’t know, or should have know, his statement would have said he had no clue whatsoever what he did. That would have been simple and direct.
His statement was that a lawyer would draft for him in order parse what and when he knew it.