I've seen shots scored after only 1 or 2 seconds. Ok, not by the same guy who grabs the rebound under his own basket, but maybe this guy makes a long pass and another guy who was already running down the court catches the ball and scores on the fastbreak.
Moreover, I think many of those "interceptions" we see during the game should unleash a fastbreak which most of the times would finish with the guy who stole the ball scoring or assisting. Though this is off the topic, I know.