Brian McDermott says Brett Delaney's disallowed try was a big turning point in Leeds Rhinos'
Challenge Cup final defeat by Warrington Wolves.
Kylie Leuluai's tackle on Brett Hodgson was assessed for a lengthy period before the score was ruled out.
The try would have put Leeds in front, but they eventually lost 35-18.
"Kylie dislodged the ball legally and it was disallowed," the Leeds coach told BBC Sport. "That was a big part of what happened in the second half."
A tale of disappointment
For the first time in Challenge Cup history, a team have suffered defeat in six consecutive final appearances.
Here is how Leeds Rhinos, who last won the competition in 1999, have set an unwanted new record:
2000: L 18-24 v Bradford (Murrayfield)
2003: L 20-22 v Bradford (Millennium Stadium)
2005: L 24-25 v Hull FC (Millennium Stadium)
2010: L 6-30 v Warrington (Wembley)
2011: L 18-28 v Wigan (Wembley)
2012: L 18-35 v Warrington (Wembley)
McDermott said of the incident: "I thought at the time that it was for a high shot. We looked at it 30 times, but Hodgson's head goes forward.
"If he'd have hit his head, his head wouldn't go forward on contact. You can put that to bed as soon as you look at the first frame.
"Then they were trying to work out if it was a knock-on, and I didn't see a knock-on from anybody."
Warrington, who were leading 12-10 at that stage early in the second half, went on to score four more tries, including three in quick succession, to race to victory.
Hodgson, who received prolonged treatment and appeared groggy for several minutes afterwards, thought the tackle from Leuluai was fair.
"Kylie's a champion bloke and there was nothing wrong with the tackle, he just got me good," said the Australian full-back, who collected the Lance Todd Trophy for his man-of-the-match performance, which included a try and five goals.
"We were probably lucky not to concede a try in that play.
"That's part of my position. Sometimes I get isolated and I have to bring the ball back to the forwards in the middle, and I cop the punishment."
Warrington coach Tony Smith, who has now led the Wolves to three Challenge Cup victories in four years, said he could understand the frustrations of his opposite number, but was pleased with the way his side reacted to the controversial decision.
"It hurts at the time and we all throw our arms up," he said. "It depends which side of the fence you're looking from to decide whether it's a good call or a bad call.
"My job is to get my players good enough to overcome the bad decisions.
"If we get a couple that go our way, I'll take them. All you can hope for as a sports fan is that it does even itself out, during the game or during the year."
As for McDermott, he will now be hoping that Leeds can shrug off their Challenge Cup disappointment by winning the Grand Final at Old Trafford in October, a feat they accomplished in 2011 after a Wembley defeat by Wigan Warriors.
"We dust ourselves off, stay tight as a group and learn from it," said McDermott. "We've got a lot of young players in that group who will have gained some valuable experience."
Challenge Cup final: Brett Hodgson try seals cup for Warrington Wolves