Mario Williams went so far through Brandon Keith that he was wearing Keith's jersey when he sacked Toast.
But the reason that Williams was able to knock Keith 23 yards backwards is that Keith was so concerned about Williams getting around him that his feet weren't set to handle Williams sudden straight on move.
Watch the play where Leinart stumbled and botched the handoff to Hightower. Even if there is a clean handoff TH is getting toasted in the backfield because a Texan defender ran around the left side of our offensive line untouched.
The Cards have had the same problem with outside rushers since Leonard Davis played Left Tackle. Whiz and Grimm have had 3 years to fix the problem and they haven't done it yet. In fact I haven't seen our offensive line play better than below average at all other than the last half of last season.
The Cards offense worked because Warner could get the ball out to our dynamite WRs, and usually the best one to throw to on that play, in about
2-2.5 seconds. For example with Warner, Williams would have hit Kurt, but the ball would have already been thrown. Most likely a dump off to the RB who is wide open on the play.
Warner out of the shotgun would be set to throw as soon as he got the ball. He would sort of slide back a couple of yards always in a position to make an athletic throw. If you have a dvr of the Green Bay game you can see this on the Amazing Fitz TD catch. (btw Warner has the ball for just about 3 seconds before throwing; and the announcer says "Warner with all kinds of time." )
Meanwhile on the play where Matt got sacked by Williams, Leinart is dropping back almost twice as far and in the same manner as if he had taken a snap from under center. He was not in position to make an accurate throw, or really any kind of throw until Williams was almost on top of him.