Manchester United manager Louis van Gaal said his side had shown “amazing spirit in spite of a nasty week” after they fought back to draw 1-1 against West Ham United on Sunday, but called for video evidence after a key refereeing decision went against his men.

The moment of controversy happened while the score was 0-0 in United’s FA Cup quarterfinal at Old Trafford. West Ham’s Dimitri Payet — who had already been booked — went down in the area after a challenge from Marcos Rojo, with no penalty given, but no red card was shown either by referee Martin Atkinson.

Payet went on to score a wonder goal from a free kick to give the away team a 1-0 lead before United staged a late fightback, with Anthony Martial equalising in the 83rd minute. That late goal was also controversial as there were claims from the West Ham camp that their goalkeeper Darren Randolph had been fouled by Bastian Schweinsteiger in the build-up.

Van Gaal said: “We have played West Brom and lost, Liverpool and lost, and then we came back. I think it’s amazing and fantastic team spirit in spite of the nasty week. I am very proud of the players and the fans are also very proud.

“I already said after the match against Liverpool, we can discuss every decision of the referee, but I can only say we are very unlucky with the decisions of the referee this season. But the man has to decide within one second and that’s more difficult than what I can do after seeing the video.

“That’s why I’m in favour of a fourth referee with a video. Then you can see it quietly. I’ve said it already, 30 years back. FIFA has to do that. They are coming now with new rules with the new board.”

Discussing Atkinson’s decision-making, Bilic said: “I don’t want to spoil the game, talking about the referee and all that. I think, overall, he has done a good job. But they did have crucial situations during the game that went against us. It should have been a penalty for Dimitri Payet. There was definitely contact.

“The equaliser, again, I’m not blaming the referee, but it was an obvious foul from Schweinsteiger on Randy. It was a foul so I was a little bit gutted about that. But I needed a replay to see that.”

Bilic said that Payet’s goal was a “perfect” free kick and looked exasperated when it was suggested that the Frenchman could have dived earlier on. The West Ham manager responded to that diving claim by saying: “Come on, come on.

If you have a screen, show me and I’m going to defend that. You can see clearly that there was more than just contact. 100 percent it was not a dive.

“Maybe the referee thought the touch was not strong enough [for a penalty]. Every decision in the box doesn’t have to be a penalty or dive.

“I’m not saying the challenge was nasty. But it was mistimed, nowhere near the ball.”

Describing the free kick, he added: “My assistants told me he scored a similar one warming up. He scored a similar one against Blackburn. I thought it’s got to be special to beat De Gea from that distance and it was pure class. A perfect one.”