Rangers withstood a fast start by Leeds and took the lead when Nahki Wells coolly finished past Bailey Peacock-Farrell on a one-on-one.
But Roofe equalised on the stroke of half-time and then had the opportunity to complete the turnaround after Bankes adjudged Toni Leistner had handled a ball over the top.
The Leeds striker duly sent Joe Lumley the wrong way from the spot to give his side a fourth straight Sky Bet Championship victory and leave McClaren unhappy with the official.
“It was a poor decision for the penalty, a very, very poor decision,” he said. “It’s cost us a result.
“Toni was adamant it didn’t touch his hand and the referee’s position - wow. He’s got fantastic eyes. He can see through people I think to see a handball.
“We go away very disappointed with the result but proud of the players in terms of their performance.”
A late winner for Norwich against Bolton meant Leeds remained in second spot but with a five-point cushion over third place.
However head coach Marcelo Bielsa insisted the Championship is still wide open.
“We go game by game and try to get the best we can from each game,” said Bielsa.
“Sometimes we get more than we deserve, sometimes we get less. This is football and that’s why it’s attractive.
“This year there is no team who have shown that they can dominate the rest of the teams.”
Bankes’ decision to award Leeds a penalty ended a 58-game wait for a spot-kick and Bielsa was impressed by the lengthy debate over who would step up to take it.
“I saw the players exchanging words and I guess they were talking about who was going to take the responsibility of taking the penalty,” he said.
“If we take into account that it’s been a long time since we had a penalty, it’s a good thing to see that more than one player wanted the responsibility.”
While Bielsa continues to play down Leeds’ promotion chances, opposite number McClaren is convinced the Yorkshire club have the staying power.
“There is big pressure and expectation and they’ve got a manager with the experience to handle that,” he said. “That’s what they’re doing.
“I think they won ugly today and that’s what you need to do when you’re going for promotion.
“You’re starting to see six, seven, eight teams coming through - Aston Villa being one of them and I expect Stoke to as well.
“There’s a lot of big clubs and only three can go up. There will be a lot of disappointed clubs with big expectations that won’t make it.
“But Leeds are going to be up there, without a shadow of a doubt.”