The spot kick was awarded by Mike Dean after Mauricio Taricco appeared to be clipped by Franck Queudrue as he latched onto Chris Perry's superb pass in the 57th minute.
Teddy Sheringham made no mistake to level the scores and we were ahead a few minutes later with what turned out to be the winner from Les Ferdinand.
"It certainly looked a dodgy penalty," said Boro boss McClaren. "I wasn't convinced by the dive, but the most important man was.
"I haven't seen it on video, but 95 per cent of the people I have spoken to said it was not a penalty. We didn't need that to go against us."
We've had to suffer some poor penalty decisions ourselves this season (notably Everton and Chelsea) and Glenn reflected: "Looking at it in the game, and that's when the referee has to make a decision, I thought it was a penalty. Looking on the video there is the faintest of brushes there.
"I'm not sure it was a penalty, not 100 per cent, but I can understand the referee giving it.
"These things are swings and roundabouts. We were denied a blatant penalty on the opening day of the season against Aston Villa, and Chelsea were given one here against us which clearly wasn't, so it all works itself out over a period of time."
Steve McClaren described the penalty decision for our vital equaliser in Saturday's win against Middlesbrough as 'dodgy'.