Paul Clement complained that Swansea should have been awarded a late penalty in their goalless draw against relegation rivals Middlesbrough.
There were five minutes remaining when Gylfi Sigurdsson's goalbound free-kick struck the arm of Adam Forshaw in the Middlesbrough wall.
But referee Bobby Madley frustrated Clement and the majority of fans inside the Liberty Stadium crowd when he pointed for a corner rather than to the penalty spot.
"I didn't see it in real time, when it hit the player the reaction of my players was 'let's go and take the corner,'" Swansea head coach Clement said.
"But having looked back at it, he clearly comes out with his arms and that doesn't look like a natural position to me.
"When you look at it in slow motion it looks like a penalty."
On a weekend when Hull, Crystal Palace, Leicester and Watford were winners in the bottom half of the table, the draw did little to ease either side's relegation worries.
Swansea are now one point above Hull, who occupy the final relegation place, with both sides having eight games to play.
Middlesbrough remain five points behind Swansea, albeit with a game in hand.
"It would have been harsh if we'd lost that game on the chances we created," Clement said of his side who were without 11-goal top scorer Fernando Llorente due to an ankle injury.
"We just couldn't get over the line. We do miss Llorente as he's a big focal point for us.
"That's not to say Jordan Ayew didn't play well, and he gives us a different dynamic.
"But when you're crossing a lot of balls into the box Llorente is a miss.
"We're hoping he will be back against Tottenham on Wednesday, it's achievable."
Middlesbrough have another huge relegation clash on Wednesday when they travel to Hull.
Injured pair Gaston Ramirez and Fabio could both be doubts for that game after being forced off at the Liberty Stadium.
But interim manager Steve Agnew says his players will be encouraged by the nature of their performance.
"We came here to win and we're disappointed we've not come away with the three points," Agnew said.
"But the attitude and intensity of the players was there for all to see and that will hold us in good stead for Wednesday night.
"The players were a little bit flat initially when they came in after the game.
"But they will gain confidence and belief from the performance and we'll take that in to Wednesday night. It's good that the game comes round so soon.
"They were a threat from set-pieces, but we were solid and we were dangerous when (Adama) Traore took the ball up the pitch and (Rudy) Gestede and (Alvaro) Negredo combined.
"It just didn't quite drop for us in the box, but I saw lots of things we can take encouragement from."