I think the red will be overturned. The "scissor slide tackle" is when both feet go in at the player with the ball. Not the case here. Kompany got the ball with his right and his left was a foot away from Nani.
City need some luck here.
Hell, I didn't think it was a penaly on any count. LOL I remember watching the steelworker ethnic clubs (Italian, Serbian, Irish, etc.) play back in the '50s and that penalty by Kompany was dainty.