I think the guy missing was Boyd or Giordano.
The play is a 3WR set. They put Routt (the number one corner) on Walter because they know the play. They've seen it before. What is supposed to happen is that Walter is looking for a pick/rub by Daniels. If not, then you get Daniels on an LB. Knowing that the Raiders will be in man, you also get the MLB out of the way by sending Foster out in the flats. The middle should be WIDE open. What ends up happening is that Daniels is double bumped, doesn't get a free release, is covered by a DB, and doesn't get in Routt's way. So where's Huff? One on one vs their #2 WR, Jones.
Giordano/Boyd was supposed to go in for Huff because he's now playing corner. Branch ends up in charge of covering the entire field as single high safety. Mitchell is in, but he's playing LB as he does in some packages. His assignment is to bump Daniels after Houston bumps him first and cover him.
Everyone plays underneath the receivers, not fearing the fade. Looking at the play again, sure Schaub deserves some blame, but the D played it perfectly (with one man down!) and Jones kinda let the team down. Schaub makes his first read (Walter) who is supposed to be wide open, but is not. He moves on to Daniels, but Daniels isn't in a good position, so he scrambles as the pocket is collapsing. When Schaub goes left, he sees that Branch is gunning for him. Branch is really fast and a sure tackler (our leading tackler). No way he escapes him, so Schaub is waiting for Jones to come back to him, but instead he just lingers for a sec, then kinda sprints right. Schaub limp wrists it to give them a chance to make a play. And, again, Huff is underneath without fear. Ball game. Schaub shouldn't have limp wristed it, but Jones should have been in scramble drill mode. He actually goes backwards and lets Huff get position on the throw.