1. On defense, Seattle's run defense was dominated in spots
At first blush, it appears the main culprits in the run game issues were Red Bryant and Malcolm Smith. Neither had his best game by my assessment. Bryant was he slow off the snap, and often struggled to get lined up when the Saints ran at high tempo. He didn't seem to really absorb double teams either. Saints offensive linemen were getting to the second level onto the linebackers with regularity. Malcolm Smith seemed to get gobbled up by offensive linemen quite a bit. He has always been good against the pass, but I'm not sure he always fills his run gap properly. When an offensive lineman gets his hands on Smitty it's basically over. Wagner's and K.J. Wright's arm length gives them a fighting chance if they can keep linemen off their body. Smith's shorter arms render him almost entirely reliant on his speed and developing play recognition.
In fairness, Seattle struggled at times against the run even with Wright on the field. It's just likely to be a recurring problem without Wright. Regardless, Red could play better, and generally does in his matchup against San Francisco. Also, fortunately, Seattle was pretty lights out in pass defense until they went pure zone late in the game.
2. On offense, Bevell is a little less culpable than I initially thought
The drive late in the second quarter is a case in point. Seattle might have blown it open just before halftime, and Bevell tried his level best. That drive featured a frustrating number of near misses. Marshawn Lynch misread a run that might have been a score or put him right at the goal line. Wilson hesitated just enough to allow Cam Jordan to push him out of bounds. And of course, Percy Harvin not only can't come down with the fingertip catch he gets lost for the game in the process of slamming his head on the ground.
In the third quarter, the offense actively tried to let the air out of the ball. Seattle simply had no intention of throwing into the wind. They were determined to run. The huge run for Turbin was called back for holding. (The flag was legitimate. I'm not even upset with Giaco though. That was a pretty subtle hold. He kept his hands within the defender's frame. Some crews would not drop that flag on principle.) That a huge play in field position terms. Just a field goal in the third quarter probably means blowout city.
In the fourth quarter, I give Bevell credit. Even some of the throws that didn't work still suggest to me that he was waiting to play the wind in the fourth quarter. Seattle's ran out much of the third quarter clock, but it wasn't premature genuflection. It was a concession to weather conditions, a good day by the offensive line, and the fact that Wilson was a little off. (Keep in mind, RW only had 18 total attempts. A good 4-5 of them were genuinely poor throws. That's not a lot for Bevell to work with.) Then late in the game they went down the field to Golden Tate in man vs. Keenan Lewis. Then of course Wilson hits the huge throw to Doug Baldwin in man vs. White. Bevell even threw by design on first down right after New Orleans scored. Bevell called plays aggressively to put the game away. I might have liked to see a bigger role for the TEs, but roughly half the plays were handoffs to Beast mode. This wasn't Bevell's masterpiece, but the gameplan wasn't fundamentally flawed. This was a lot closer to a blowout win than the final score indicates.