Although the incident has not been highlighted, when pressed, Glenn says that Darren Purse's actions in pretending to be injured after Steve Lomas' goalbound shot was blocked by the defender's hand deceived the referee into not giving a penalty.
From the Dr Martens stand - Glenn's vantage point - it looked to most as if Steve's thunderbolt had all but knocked him senseless.
But on inspection of the video, it is clear that Purse not only stops the effort with his hand but then immediately feigns injury to his head to divert the possibility of the ref giving a penalty.
In typically understated manner, Glenn says: "We'd have had to have scored the penalty first."
But, having seen his side score five out of five at Chesterfield, that may well have been a formality.
And, while stressing that he is not looking to cloud the problematic issue of the performance in the defeat by Birmingham, he does admit: "I am 100% sure that his hand stopped the shot going in - but he was very 'clever' with his reaction in making out he was hurt."
He goes on: "Let no one make excuses. I am prepared to stand out there and take my responsibility, but I am looking for the men in the team to take theirs and not hide behind me.
"It is very frustrating; players that you could rely on last year not to make mistakes are making mistakes.
"But there comes a time when they have to take that responsibility themselves, and the players have to do that - like men.
"We have three or four players who haven't performed anywhere near how they performed last year, that have underachieved, and not produced what they should do for the positions they play in.
"Every position has a responsibility to the team. If you are a defender you defend, if you are an attacking midfield player you have to create and maybe score yourself...they have got to shoulder those responsibilities, come out, and show they are prepared to fight the way they did against Chelsea.
"People who haven't played as they should have - or were expected to - this year should look at the Chelsea game."
As far as changing personnel is concerned, Glenn is understandably reluctant to talk about possible transfers with the window not opening for another three months.
But he is looking to shuffle the pack within the squad, and reveals: "I've got to find a back four that defends and that leads me to bringing Ian Pearce into the team when we return to action.
"He has shown admirable patience and he deserves a run in the team as we look to get more solid in front of David James."