The guy was in the pile, while the guy blocking Schmidt is already engaging Schmidt. He gets hit from behind which causes him to Superman foward, getting knicked by Martini onto Schmidt's leg.
Now, I'd love an ariel view of the play. My assumption is that he initially was doubling on the DL and trying to scrape to the LB (maybe). But if that is the case, he needed to get off that block much faster, because the RB is on his back (as it's a FB dive read from the QB). If his assignment was really to block Martini there, he screwed it up pretty bad, because he didn't get to the next level very quickly at all.
But that wasn't a cut block, there was contact from behind, from the RB/pile that propels him forward. In real time, you can see him get bounced out of the pile, and from the screen caps in the post above, you can see that the RB is on his back and has run into him. If his assignment was to block Martini, he was really really really really late getting there for a FB dive. I'd love to see the diagram that has someone attempting to cut block the backside LB for a FB dive.