Arsenal boss Arsene Wenger was furious with ref Andre Marriner after their 3-0 home demolition by Chelsea.
Wenger hit out at the referee for ruling out Andrey Arshavin's goal shortly after half-time for an apparent foul by Eduardo on Chelsea stopper Petr Cech.
The Blues were 2-0 up at the time following Didier Drogba's opener and a Thomas Vermaelen own goal. Wenger said Marriner had told him he gave the foul because Eduardo kicked the ball out of Cech's hands as both players went for a cross.
When the ball came loose from the clash it fell to Arshavin, who put the ball in the net only for Marriner to blow up for the foul.
Wenger believes his side could have gained a vital foothold back into the match if the Russian's goal had been allowed to stand.
"The turning point was the referee's decision (to disallow the goal)," Wenger said. "Personally I believe it was not a serious decision, that was very unfair. How can he see Eduardo kicking Cech when it was a Chelsea player who stops him from controlling the ball?
"It would have been a very important goal in this kind of game and that was a big mistake by the referee. When you start the second half of the game 2-0 down instead of 2-1 down, it's psychologically completely different for the security of Chelsea."
The Frenchman believes the goal would have been allowed had video technology been in use.
"You can see on the replay that Eduardo doesn't even intervene. He said to me it was dangerous play, that Eduardo had kicked the ball out of Cech's hands. He is not even in there, Eduardo.
"It's important that in big games referees do not make big mistakes and influence the result and today it was a mistake from the referee. Apart from that he was fair and tried to be fair but he made a massive mistake at a very important point in the game.
"I personally think the referees do not want video. It's difficult to understand why. Why doesn't he ask for video today when. Why? Nobody knows because they are scared to be intimidated and they are worried about being under pressure when they are looking at video."