Penalty Kick and Yellow Card

Red 16 makes a genuine attempt for the ball but fouls the Blue 7 in a DOGSO situation (Denying Obvious Goal Scoring Opportunity), despite the Referee have optimum viewing angle, he is advised by the Assistant Referee incorrectly that a Red card is to be shown. 

To the credit of the Assistant Referee he realises the error and that the offence is only punishable by a Yellow card, as play has not restarted the Referee is allowed to correct his decision. A messy situation but the right outcome.