Regardless of how bad a tackle it was, and imo it was an awful one (just watch how Gio's leg seems to buckle a bit before it slides back), it was at the final whistle. And Cambiasso knew it was the final whistle, and that there was no chance they could take the ball downfield and score. Why was it even necessary to go in for a sliding tackle when you know the game is already over. He obviously did it out of frustration with losing, and with malicious intent to send a message/injure a player. He should be banned for the rest of the season for that.