Three-point attempt at clock expiration hits floor; bounces through basket

[goodros_nemesis]

Down by two points, team A has the ball at their own endline with two seconds remaining in the fourth quarter. A1 inbounds the ball fully into the backcourt where player A2 runs to catch it. A2 catches the ball and turns to heave up an almost-full-court shot. The ball is well short of the target and bounces off the floor and then goes through the ring just before the buzzer sounds.

Does the basket count? If so, is team A awarded two or three points? What if the buzzer had sounded before the ball bounced?

This actually happened to an official in the Utah Wasatch Chapter in a game last week. Talk about once-in-a-lifetime...