Eh, it was a mistake, but not the worst I've seen. He whiffed because he was too early. Had he hit head on at speed he would've drawn PI and the game would've most likely ended with a Vikings FG.
It's also because of Marcus Williams that the Saints were even in the game; he intercepted Keenum in the third to get the Saints to 14. If we want to get even more detailed, we could've been up two scores if Brees hadn't thrown 2 picks in the first half.
The Saints secondary is almost entirely rookies or new players. Only Rafael Bush has played for more than 4 seasons, and he's not even a starter. Live by the rookies, die by the rookies.
I'm proud of how far they came this season, even if their mistakes made for a painful ending. If we can draft a QB to take over when Brees hangs up his cleats, the Saints as a whole are young enough to be a force in the NFC for years. They'll need to be, the Conference isn't going to get any easier. Next season will have the Packers with Rodgers, Carson Wenz back with the Eagles, a more experienced Rams, 49ers, Redskins, Cowboys, Panthers, and Seahawks.