1. When a pass is received by both the receiver and the defender, it should be called an incomplete pass
2. Guarding the receiver should be allowed by the defender unless he makes forcible contact or interfere with the arms of the receiver, even if he is not playing the ball. I think the rule is already like this, but this is not called with consistency. This is particularly bad when the receiver initiates contact trying to catch an underthrown pass and the defender is called with the PI.