World Cup - Welsh blame referee for loss
Irish referee Rolland sent off Sam Warburton for a dangerous tackle in Saturday's 9-8 semi-final loss to France at Eden Park.
Gatland conceded Warburton deserved to be penalised for illegally lifting France winger Vincent Clerc but blamed the referee for his team's agonising defeat, saying he had made a grave mistake by issuing the Welsh captain a red card.
"Having looked at it, we accept it that he lifted him and it warrants a yellow card, but he doesn't drive him into the ground," Gatland said.
"The thing that surprised me was the referee's instinct. I thought an experienced referee would bring in to the two touchies (assistant referees) and have a chat then make a judgement."
Although Warburton lifted Clerc and dropped him on his back in breach of the game's strict laws on foul play, the flanker defended himself, saying he had not intended to drive the winger into the ground.
"I am obviously gutted with the red card. There was nothing malicious. There was no intent," Warburton said.
"I thought it was a normal tackle and the next thing you know I'm walking off into the stands."
Wales defensive coach Shaun Edwards was also fuming about the decision but said there was little point in complaining.
"I think it's a travesty for the competition because the team that should be playing next Sunday isn't," he said.
"(But) in times like this it's important to keep your dignity and not to say what you think."
Despite being reduced to 14 men for most of the match, Gatland said his team still had the chance to win the game and advance to their first World Cup final.
Flyhalf James Hook missed two penalties and his replacement fly-half Stephen Jones struck the left upright when he attempted to convert Mike Phillips' 59th minute try.
Wales also missed two drop goal attempts and full-back Leigh Halfpenny missed a long-range penalty shot in the last 10 minutes.
"When you get two quality teams and one team goes down to 14 men then the other team should win the game comfortably," Gatland said.
"But we had some shots at goal and a conversion that gave us a chance and I can't be more proud of our guys in terms of what they achieved when they were down to 14 men inside the first 20 minutes.
"It was absolutely courageous what they did to push France that close and nearly win the game."
Wales scored the only try of the game and dominated both territory and possession but ultimately contributed to their own defeat by their failure to take their opportunities.
They lost five line-outs on their own thrown and a scrum on their own feed yet still had the chance to win the match even in the last minute with a 26-phase play that came to nothing.
"We didn't feel at any stage that France posed us any problem in the tackle," Gatland said.
"We've got to take it on the chin, it's no discredit to France because they didn't make the decision ...in credit to them they defended well.
"Our players ran themselves into the ground with 14 men, you can't ask for any more."