Cary Williams is a really good corner which is why it is mind boggling when you see him have costly screw ups. I don't want to say he single handedly almost lost the Super Bowl but he had three bad plays that either were costly or could've been costly. He was the one along with Bernard Pollard that missed the tackle on Michael Crabtree when Crabtree caught the ball and bounced off two tacklers then ran into the end zone. He also had a big screwup not disengaging from his coverage in time to come help contain Colin Kaepernick as he scrambled 15 yards to the end zone. And finally when the 49ers were 5 yards shy of taking the lead, on the first play near the goal line he took a bad step and allowed Randy Moss to get wide open on a drag across the back of the end zone. Kaepernick on the roll never saw him and so he didn't throw it, but if he did...that's the go-ahead touchdown.