Mods, you can merge this if needed. I didn't know if there was an "official thread" for this.
The statement from Joel Litvin, NBA President of Basketball Operations, reads:
"After reviewing the video of last night's Pistons-Magic game, we determined that the play that concluded with Chauncey Billups' three-point field goal at the end of the third quarter took approximately 5.7 seconds. Because there were only 5.1 seconds remaining in the quarter when the play began, the shot would not have counted had the clock continued to run.
LINK