[just another ref]

Gotta back Nevada on this one. Touching the rim has no part in the definition.
On the other hand, the limiting factor is physics. It is pretty near impossible to perform a dunk without touching the rim. If this guy was in fact dunking without touching the rim, (driving, forcing, pushing or attempting to force a ball through the basket with the hands) he is either an extremely gifted athlete, or the dunks weren't much, as dunks go.

By Rich's own description, dropping, lightly pushing down, I might very well agree that they weren't dunks, but the lack of touching the rim alone is not what makes that true.

The key, as I read the definition, is pushing through the basket, which means pushing down. Saw a highlight recently where a player, I think it was Tyrus Thomas, threw it down through the basket even though he released the ball several feet in front of the rim. Was this a dunk? I think so.