Toward the end of regulation in the Louisville/Marquette game tonight, a Marquette player grabs a missed shot on a fast break and attempts to dunk. The rebounding player is fouled by an opposing player and grabs the rim, apparently to protect himself from falling. The dunk shot does not initially go thru the hoop, but after deflecting off the rim then the backboard it goes thru the hoop (about the same time the player releases from the rim).
The referees initially wave off the basket, then decided to count it, then after conferring for awhile, negate the basket again (player did get 2 free throws of which he made 1). Marquette lost in O.T.
Given the circumstances described above, should that backet have counted?

Did the player pull the rim down from it's normal position?

It did deflect down some, but not any more than on an average dunk shot.

Sounds like basket interference on the offensive player was the call.
Here's the rule. You saw the play. You can decide for yourself, if the action meets the definition provided.

Rule 4, Section 4. Basket Interference
Art. 2. Basket interference also occurs when a movable basket ring is pulled down by a player so that it contacts the ball before the ring returns to its original position.

Rule 9, Section 17. Basket-Interference and Goaltending Penalties
...
Art. 3. When the violation is at a team’s own basket, no points shall be scored and the ball shall be awarded to the offended team at a designated spot nearest to where the violation occurred.

If he pulls it down and it hits the ball as it snaps back into place, it's basket interference.

I saw the game on TV. I didn't hear an explanation from the announcers (but I was in a sports bar). But from watching the replays the officials had to have ruled offensive basket interference b/c the player did collapse the rim on his dunk attempt and as the rim was snapping back into place it appeared the ball may have grazed the back of rim while going through the hoop.

If the player (still) contacted the basket while the ball was in the basket, then it's BI.

From reading the posts, that sounds more plausible then the "pulling the ring" scenario.