I don't even think he was trying to set a pick there, was waving for the blitzing SAM and clearing out, Sask DB ran through him but Demski was just pointing for the blitz so looked like he stuck his arm out to catch the defender.
Not true. Otherwise guys would be setting screens all over the place on downfield passes.
But in this case, the ball is basically in Mitchell's hands when Demski drives into the DB.