Sanchez moved left then he moved right then he just sat there and finally he just decided to fall down. He had plenty of time to either move and extend the play or throw the ball away. A QB with pocket presence would have thrown it away or extended the play. But given the down and field position it hurt nothing sitting down and taking the sack. Given Sanchez's TO problems and the state of the Chiefs offense punting is not a bad thing.
On that last safety blitz? Look, I'm watching this game on my laptop but it sure seemed like the S got there very quickly. Certainly in less time than it would've taken Sanchez to extend the play. I agree he did the smart thing in taking sack, but I don't think he had much of a choice.