There was a definite turning-point in the game between the 49ers and the Saints. Just as Colin Kaepernick had bobbled a low snap and in-turn threw an interception, the momentum seemed to be in New Orleans' favor. Halftime was approaching and even though San Francisco would get the ball back to start the second half, Drew Brees and his offense would get a chance to score before the first half ended.
In baseball we used to come back into the dugout after hitting a ground-out or pop-fly and holler to the next batter "pick me up!" It meant for the other guy to help you out, try to make your mistake less of an issue by getting on base, hitting a home-run, driving in a runner, etc. I'm guessing that Kaepernick was thinking this and possibly even said something to that effect as his defense was coming on the field following the interception he threw.
Ahmad Brooks probably heard it, even if it was unspoken.
On the second play of the Saints' ensuing drive, Brooks would do something he usually doesn't do: drop into coverage rather than rush the passer. Obviously it was Vic Fangio's call, but his linebacker executed it to perfection. Below is the All-22 film angle, gif'd up so we can take a look at how Brooks baited Brees into the throw.
As you can see, Brooks is lined-up over the gap between guard and center, showing blitz. The 49ers rush just three and Brooks drops back shallow, about 5 yards from the line of scrimmage. The rest of the coverage looks like zone, with Patrick Willis dropping back and giving cushion to the receiver in front of him. NaVorro Bowman reads the QB's eyes and jumps the TE, figuring it's an out or short dig route, but it's actually more of an out-and-up.
Brees watches Bowman jump the out route and knows his TE is going to turn it up field now that the defender bit. What he doesn't see is Brooks is spying him the whole way. There's nobody in the center of the field for Brooks to cover, so he reads Brees' eyes and jumps the throw. It's a throw that Brees shouldn't have made, but my guess is that the Saints' game-planning and film-study didn't notice Brooks dropping into coverage from this look.
Brooks is baiting the QB by taking a straight-drop with a receiver who was entering the middle of the field from the top of the screen. I'm guessing that Brees expected him to stay in the center of the field and come up to stop the inside route, but Ahmad knew where the QB was going with the football. He made a great jump on the ball and showed good hands to pluck the ball out of the air with his hands. He then showcases his speed by outrunning everyone 50 yards for the touchdown.
I also don't understand why Brees threw the ball so quickly here. There was a clean pocket with only some minor pressure coming of the left side. He hadn't been sacked yet in the game, either. The safety is also coming up and actually arrives just as the ball would have. It's definitely a throw into coverage, even without Brooks' presence. It looks to me like Brees respected the 49ers pass-rush even before they got to him for a sack.
Whatever the case may be, it was clear that Kaepernick appreciated Brooks "picking him up", as he was one of the first to greet the LB on the sideline after the play.
It's also worth noting that Brooks had a pick-six in a 2011 pre-season game against the Houston Texans in Candlestick Park. Perhaps his time at inside linebacker in college and with the Bengals lends itself well to these type of plays where he comes inside. Let's hope we see more of this from Fangio and Brooks.