Gary Neville says Mike Dean's "head was a mess" after sending off Sofiane Feghouli in West Ham's 2-0 defeat by Manchester United.
Feghouli was sent off for a challenge on Phil Jones after 15 minutes, before goals from Juan Mata and Zlatan Ibrahimovic, who was offside, sealed the visitors' win.
Although insisting the red-card decision was not the worst he's seen, Neville says Dean "went to pieces a little bit" afterwards as he failed to give a card to Cheikhou Kouyate for a lunge on Henrikh Mkhitaryan.
Neville said on Sky Sports: "I think it's maybe the reaction of the Manchester United players, the reaction of Phil Jones maybe, obviously who no doubt would have taken a kick and would have been hurt by it.
"It's a poor decision, and I actually think that the Kouyate tackle in the second half was a red card, where he goes over the top of the ball on Mkhitaryan. It's far worse; it's a definite leg-breaker, with his studs showing.
"His head was a mess after that Mike Dean, he's had a really poor day, and to compound that the linesman has too, with Ibrahimovic offside for the second goal. It's not been a good day for the officials, Manchester United have benefited from that today.
"Slaven Bilic, I'm sure, will be furious. It's very difficult when they get one shot of it, and we get four or five. But in the stadium here, I must say, nobody thought it was going to be a red card.
"Everyone thought when the red card came out, wow, because it didn't feel like a red card moment."
West Ham will feel aggrieved that Ibrahimovic's goal stood, with the Swede clearly goal-side of last man Winston Reid before slotting home the second.
Neville added that he is for video technology in football, but questioned in what instances it can be used.
"I'm for video technology, I have been for a long time, the question is just how you use it, when you use it, in what instances.
"There have been far worse decisions than that, we're not talking about the most shocking decision of all time here, I mean he has lunged in, and Mike Dean will defend himself.
"His performance after the red card was the most disappointing thing, because he went to pieces a little bit."