Keith Hill claimed referee Chris Sarginson was wrong to award a penalty to help table-toppers Cambridge grab a 1-1 Sky Bet League Two draw at fellow high flyers Tranmere.
Paul Mullin’s spot kick on the hour was saved by Joe Murphy but the division’s top scorer netted the rebound to equalise.
However, Hill, whose team jumped above his former side Bolton into third, was insistent there had been no foul on Luke Hannant.
“We were definitely done by a mistake by the referee,” he said. “There is no way a penalty should have been awarded.
“We are really disappointed in respect to the referee giving a penalty.
“None whatsoever,” added Hill when asked what he believed the spot kick had been awarded for.
“The magnitude of that decision could be really costly for Tranmere Rovers and this group of players.
“I thought we played really well in the first half and we battled well.
“It was a positive performance on the back of what could have been a confidence sapping result against Cheltenham,” he added of the 4-0 Good Friday whitewash in Gloucestershire.
“I thought the players gave us everything. In the first half we should have at least put another opportunity away.
“But that’s been a problem with us being without James Vaughan.
“While we are treading water results wise and staying in there, we are hopeful we can get him back shortly.
“I think if James Vaughan had played we win that game comfortably.
“We need a bit of quality in the final third. We might not be getting it at the moment but we will and it will turn in our favour.”
Tranmere’s 21-goal marksman has not played since February 27 and is recovering from knee surgery.
Cambridge boss Mark Bonner said of the penalty: “I haven’t seen it back but my analyst tells me it was one. So, I will have to believe him.
“The boys thought it was, their reaction suggested it wasn’t. So, I can’t comment until I see it.
“But we are delighted it gets given. It was tough for him (Mullin) because he had to re spot the ball about four times because it kept rolling off.
“So, he has done well to connect with the rebound once it been saved initially. It was a big goal for us.
“It was a tough afternoon and Tranmere played well in the first half. We lacked the intensity we wanted to play with and it became hard for us.
“We played better in the second half when we were more aggressive and a little stronger. Probably on the balance of play a draw is about right.
“At the end of a busy week and to come here and take a point we are really pleased with that.”