Barnsley boss Valerien Ismael was furious his side were not given a penalty in their 0-0 draw with Nottingham Forest.
Chris Hughton’s Reds spurned some golden chances to take all three points against the Tykes, with Lewis Grabban, Sammy Ameobi and Anthony Knockaert all going close.
But the visitors felt they should have had a spot-kick when Michal Helik appeared to have been pulled back in the box by Joe Worrall, only for referee Leigh Doughty to wave away their appeals.
“It was a really, really big mistake and a game changer. We need to have a clear and proper decision, so it is a big frustration,” Ismael said.
“We are frustrated by the point, even if we saw a lot of positives.
“I do not want to speak about all the small decisions in the game, because that can happen. But such a big, big mistake… I cannot explain what has happened. It was clear. Everyone saw the same situation. We are not stupid.
“It was a clear penalty for us.
“It is unacceptable, the performance of the referee. You have to do something, you have to say something. We are fighting to win, which is why it is such a big frustration.
“The penalty could have been a game changer for us.
“It was a good clean-sheet and we will take the point.
“In the second half, we had a really good chance to score and (Brice) Samba made a great save (from Cauley Woodrow). But the big frustration was about the referee’s performance.
“I did not speak to the referee. But this was a game changer for us.”