Barry Ferguson has revealed he was left reeling at the decision not to award Rangers a penalty during last week's Old Firm derby.
Alistair Johnston appeared to handle the ball inside Celtic's box as the Canada international knocked the ball away from Abdallah Sima. This was missed in real-time.
Willie Collum checked the incident on VAR, however, after a short pause to the play, he alerted on-field official Nick Walsh to continue the game.
Later on Saturday afternoon, it emerged that the decision had not been overturned due to Sima being in an offside position.
Since then, Rangers and the Scottish FA have held discussions over the incident, with both parties portraying the contents of the meeting in different lights.
Ferguson admits he was left screaming at his TV when the decision to play on was made.
And the ex-Ibrox captain cannot blame his old club for questioning the powers that be over the call.
He wrote in his Daily Record column: "Sometimes it’s hard to know where to start once Scottish football starts kicking itself to bits. We’ve been here before after all.
"But, for once, that’s not the case where this ongoing row between Rangers and the SFA is concerned. It’s obvious. It all begins from the moment that Alistair Johnston blatantly punches the ball inside Celtic’s penalty box and a terrible decision is made to pretend it didn’t happen.
"But what came next - over the course of almost half an hour - has now brought the game in this country back to boiling point with my old club demanding answers from the men in charge at Hampden.
"And I must be very clear here, I don’t blame them one bit. What we need in this country, where VAR is concerned, is less secrecy and more transparency. But what we got at Celtic Park during that baffling 30 minutes, was completely the opposite. What seems obvious to me is that the process broke down at a critical moment in a massive match.
"First of all, I have no issue with Nick Walsh for not spotting the hand-ball in the first place. These things happen in the heat of the battle and especially in a frantic, high tempo Old Firm match. The man in the middle has an almost impossible job to see everything as it happens and call it all correctly. He’s only human.
"But what seems clear is that he believed the ball had gone out of play off Abdallah Sima because he awarded Celtic with a goal kick and that’s how Joe Hart restarted the match. All of which was wrong. There’s no grey areas there. It’s a simple case of black and white.
"The whole point of VAR - and the reason the clubs are paying for it - is because at that moment the process is supposed to kick in. Willie Collum could see from the replays that the ref had made a clear and obvious error because Johnston’s hand got the final touch.
"For the life of me, I can’t understand why he didn’t call Walsh over to the monitor at that point to take another look for himself and then make a decision based on replays that weren’t available to him at the time. If the procedure is working properly then, while the referee is at the screen, the guys in Clydesdale House run checks to see if there was any offside or pushing or pulling in the immediate build-up.
"So they would have clocked at that point that Sima had drifted into an offside position when John Lundstram was clipping the ball back into the box. And the whole thing would have been put to bed in the space of a couple of minutes.
"We certainly wouldn’t be sitting here arguing about it six days later. It would have been done and dusted and there would have been no need to discuss if Johnston’s arm was moving ‘unnaturally’ or not. Which it undoubtedly was, by the way.
"I was screaming at my TV for a penalty at the time. Even Neil Lennon admitted during the half time break that he would have been boiling if it wasn’t given to his side. And that’s the former Celtic captain and manager we’re talking about!
"But, regardless of whether the decision was correct or not, it beggars belief that the broadcasters were then told, 15 minutes into the second half, that the lines showed that Sima was in an offside position to begin with.
"That’s not proof that the VAR process was working properly. It’s proof that the whole situation had been mishandled. So Rangers are right to ask questions over what went on even if I’m a little uncomfortable with the calls for Collum not to be allowed to officiate in any of their games from this point on."
