Marriner was wrong to send anyone off because Oxlade-Chamberlain didn't deny an obvious goalscoring opportunity... again, we NEED video replays to help referees

Andre Marriner said he was wrong to send Kieran Gibbs off as it was a case of mistaken identity - replays confirmed what most observers saw at full speed as Alex Oxlade-Chamberlain was the Arsenal man who handled the ball.
However, with the ball seemingly going wide I do not think either player should have been dismissed as there was no denial of an obvious goalscoring opportunity. 
 
Admission: Oxlade-Chamberlain even approached Marriner to tell him it was he who handled the ball
Marriner did well to detect the devious handball as Oxlade-Chamberlain dived full length and tried to head the ball.
He stated that it was his decision and his alone and while I would accept that from where assistant Marc Perry was standing it was very difficult to see the handball I would expect him to keep his eye on the player and let the referee know who it was to ensure the correct player was dismissed.
It was good to see that Oxlade-Chamberlain admitted to Marriner that he had handled the ball in an attempt to get the Midlands referee to change the red card shown wrongly to Gibbs, but unless one of the other officials tells the referee of his error he will stick to the original decision.