[Andy]

Well, you've received the philosophy and the rule book reference. I agree with everything said so far and add this:

You mentioned that the blocker contacted the top of the net. It's very possible that your partner may have been focusing on the blocker's body as she was coming down or on her feet to make sure that she landed without crossing the center line. As a down official, I will start to transition my focus to the botttom half of the net and the feet shortly after the attack. It's easier for me, on the floor, to see the contact with the body on the bottom part of the net and, of course, the feet on the floor. The referee, on the stand, has to follow the ball. Often, I will miss contact with the top part of the net. The referee needs to make that call if the R2 does not blow his/her whistle after a short pause. Just remember, if you make the call, you should be able to tell the coach which player was in the net.