I thought so as well considering Kompany had all ball but the announcers cleared up my understanding. They said 10 years ago that's not a penalty, it's a good tackle. Now, if you go in with two feet (not saying I thought he did), you'll get tossed.
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.