Correct me if I'm mistaken but the goal in basketball is to put the ball in the basket, and a dunk doesn't require ripping down the rim - in fact pre-breakaway rims guys didn't grab rim as often as they do now. So basically the rim grabbing is regain your balance and sound effects. Not absolutely necessary for a dunk. This might have been a tiny bit of throwing the ball into the basket but he doesn't let go until his hand is at the rim, so I think that's nitpicking as soon as he touches the rim (and Perkins fouling him is what prevented a rim pulldown).
I don't know whether its among all time dunks (context? put it in playoffs and absolutely), but it merits discussion. Its certainly the best dunk of the year especially when grading by 'talked about' and message for dunking over one of the leagues notorious tough guys.