The game’s turning point was Anthony Taylor’s decision to upgrade Casemiro’s initial yellow card to a red card after consulting the pitchside monitor for a lunge on Carlos Alcaraz towards the end of the first half.
The match was full of controversial decisions, including Armel Bella-Kotchap’s unpunished handball in the box, which the VAR officials and Taylor deemed undeserving of a penalty.
In the second half, Marcus Rashford had a softer claim turned down after a slight touch by Gavin Bazunu inside the area.
Ten Hag was frustrated with the officials’ performance and expressed his grievances post-match.
“What I think is the inconsistency, players don’t know anymore what is the policy,” he said. “I think, all across, you see this weekend yesterday Leicester vs Chelsea, VAR is not coming on the line.
“Today it is coming on the line and today two penalty situations they don’t come on the line. I think especially the first it is clear and obvious handball. So, what is the policy?
“There is another one [that is] inconsistent. The refereeing is coming at the start of the season with a policy: ‘We are Premier League, we are going strong and want intensity’.
“Casemiro is across European leagues in over 500 games – he never had a red card and now he has twice [been sent off]. He plays tough but he plays fair. Also in this he is playing fair. Also against Crystal Palace. It is very debatable.
“When you freeze it looks bad,” Ten Hag added, on the dismissal against Southampton. “But everyone who knows something about football, they know what is bad and what is fair. Casemiro is a really fair player, tough but fair. It shows, over 500 games in big leagues, never sent off.
“When you act like this you have to be consistent across all the games and all the decisions. Now they isolate one. A little bit the same as against Crystal Palace. When you show that incident, you should have sent off, when you are consistent, three, four players and not only one.”
When asked if Manchester United would appeal the red card, Ten Hag replied: “We will see”