That play reminded me of the one last year on MNF where the Dolphins seemingly "allowed" the Steelers to score right before half time. At the time, the Dolphins were the laughingstock of the NFL and presumed to be in line for the #1 pick. In either case, the defense called was curious, to say the least.
In defense of yesterday's game, there was too much time left to be thinking Hail Mary there, and the offense did not line up in a typical Hail Mary set, where there are several WRs on one side of the field. Given 13 seconds, the more likely expectation was an out route to pick up 10-20 yards and shorten the field. The Cardinal Sin was the CB biting on the shorter pass fake. You have to give him that break and then see if you can get there and defend the pass or wrap up the WR. If he catches it, he catches it. You can't bite on that and allow the WR to get by you.
On a final note, breaking news has Gregg Williams fired this morning.