It looked like the Saints and Buccaneers would be heading to overtime when Josh Freeman found Mike Williams in the back of the end zone on the final play of the game. Instead the play was ruled a no-catch and the game ended with a 35-28 Saints victory.
So how did the Saints dodge a last-minute bullet? As David Fucillo explains, Mike Williams was not allowed to be the first to touch the ball after stepping out of bounds.
According to Rule 8, Section 1, Article 8 of the NFL Rule Book (PDF), "[i]t is a foul for illegal touching if a forward pass (legal or illegal), thrown from behind the line of scrimmage ... (b) first touches or is caught by an eligible receiver who has gone out of bounds, either of his own volition or by being legally forced out of bounds, and has re-established himself inbounds.
Important to note also is that cornerback Patrick Robinson was allowed to shove Williams out of bounds because quarterback Josh Freeman was out of the pocket. Per Rule 12, Section 1, Article 6 - (PDF):
Note 1: Once the quarterback or receiver of the snap hands off, is tackled, throws a forward or backward pass, loses possession of the ball by a fumble or a muff that touches the ground, or if the quarterback leaves
the pocket area (see 3-24), the restrictions on the defensive team relative to offensive receivers (illegal
contact, illegal cut block) will end.