With the second-leg of the semi-final delicately poised at 1-1 on aggregate, the Scotland international was shown a straight red by referee Roger East for blocking Nathan Redmond’s goal-bound effort with his arm.
Wes Hoolahan converted the resulting spot kick and, despite equalising momentarily through Tommy Smith, the Canaries sealed their place at Wembley with further goals from Redmond and Cameron Jerome.
And McCarthy, who felt his side may have been awarded a penalty themselves in the first half, was left unanimous as to what caused his side’s demise.
“We’ve had a terrific season. I thought we played really well here today, certainly in the first half,” he told Sky Sports.
“But games are won and lost on decisions, aren’t they? I thought we had a penalty in the first half when Teddy Bishop was brought down.
“Then they got a penalty and a sending off which changed the game.
“No complaints – he’s handled the ball on the goal line, it’s a red card. I have complaints about ours though; I think ours was a penalty. He doesn’t give it; he obviously doesn’t think it is a penalty but he’s got it wrong.
“In the cold light of day, of course, Christophe should have let the ball go in, but we’re programmed not to let the ball into the net, it’s one of those things, it’s cost us but there’s not a lot we can do about it now.
“We didn’t need to give a penalty away and get someone sent off and we needed to get our penalty. The game has hinged on a sending off and a penalty.”
Despite failing to reach the Wembley showpiece, McCarthy was pleased with his side’s performance at Carrow Road, and quickly refocused on mounting a successful promotion push next season.
“I’m immensely proud of the team, we’ve had a great season and I look forward to next now,” he added.
“We were cool at half time, we played really well and I thought we were the better side.
“I’ve enjoyed the play-offs, I can’t say we’ve been beaten by a better side, we’ve played really well it’s just incidents and occurrences on the pitch, and the fact we had ten men, that have cost us.
“This season proves to me what a good bunch of lads I’ve got, and the club is great – it has been terrific all season long.
“There has been a great spirit about it and we’ve got to come back and keep that going next season.”