Bristol City went down 4-2 at Barnsley with Robins boss Keith Millen citing a dubious penalty kick which brought the home side level as being the turning point.
Millen criticised the officials for their handling of the incident, saying: "It's hit Marvin (Elliott) on the side of the hip and that's what annoyed the players.
"The referee saw it as a penalty because he was facing it but the linesman didn't see it as a penalty.
"I can understand the referee making the decision but with the linesman, they are supposed to communicate when they are miked up.
"You would think between the two of them they would get the decision right.
"Up to the decision I was delighted with the performance, we should have scored more goals in that period.
"We looked really dangerous and then the penalty decision - the manner of it upset our lads - and we lost our focus and Barnsley punished us. To come in at 3-1 down at half-time was unbelievable."
He added: "We should have been 2-0 up before they scored. I was really pleased for the first 20 minutes.
"The third goal was a poor goal to give away, we should have cleared the ball before it got to him.
"We didn't show enough aggression at corners to get at the end of the final ball.
"We should have had more goals but the credit to the lads, their heads didn't drop. They are really disappointed."
Barnsley counterpart Mark Robins challenged his team to end the season with a flourish.
He said: "We've got 18 more points to play for and at this moment I think 68 is achievable.
"After you win you think you can conquer the world and as long as you work hard you're going to get your rewards.
"Next we've got to emulate Scunthorpe and beat QPR on Tuesday night.
"I thought the atmosphere at the ground today was good and I want us to play attacking football."