The Scottish Football Association's chief executive has reiterated calls for the introduction of goal-line technology.
A Lee Wallace header was clawed away by Celtic keeper Fraser Forster after six minutes of Wednesday's Old Firm game.
And Stewart Regan reckons cameras may have clarified whether the whole of the ball crossed the whole of the line.
"Another example where goal line technology would have been useful," he wrote on Twitter.
Referring to trials of goal-line technology which are being carried out by an independent testing authority employed by Fifa, Regan added: "Test results will be discussed at IFAB meeting in March."
A final decision is expected to be made in July 2012.
Television replays were inconclusive as to whether the goal should have stood, highlighting the difficulty facing referee Willie Collum and his linesman in making an instant decision.
But the Rangers manager Ally McCoist was convinced, and believes the technology would have proved him right.
"I have seen it and it has definitely crossed the line," he said.
"Sometimes you get it and sometimes you don't but I will keep that for another day. We have to take that on the chin and get on with it.
"I think Lee and Nikica Jelavic were both fairly convinced that the ball had crossed the line but there is no use mumping and moaning about it."
Celtic's 1-0 victory at Parkhead means they top the SPL table for the first time this season, despite Rangers establishing a 15-point lead on 5 November.