Celtic striker Leigh Griffiths claims referee Bobby Madden asked him if Rangers defender Clint Hill got a touch on the ball after ignoring a Hoops penalty appeal in the 1-1 draw at Parkhead
Hill had sensationally levelled in the 88th minute of the Ladbrokes Premiership clash after midfielder Stuart Armstrong had fired the home side ahead before the break.
In added time, as the runaway league leaders drove forward for the winner, the 38-year-old full-back challenged Griffiths in the penalty area as the striker tried to get a shot away and although the Hoops substitute went down, Madden took no action.
Griffiths said: "It was a penalty. He has not touched the ball and the referee is asking me afterwards if he touched the ball.
"If he has not touched the ball he has got to give a penalty or book me for diving.
"I am going to put the ball in the back of the net.
"He has caught me at waist height, he has not touched the ball. It is a decision that cost us the three points.
"Bobby Madden is the only one in the stadium who doesn't think it is a penalty but it is over now, we can't dwell on it. It is another point towards the title."
Celtic manager Brendan Rodgers claimed Hill told him on the pitch after the game that he should have been penalised.
The Northern Irishman said: "It was very frustrating, especially when Clint Hill tells me that he got away with it.
"Clint is a good guy, honest fella, and I know when he said it he knows he got away with one.
"We obviously should have had a penalty right at the death, it was a clear-cut penalty.
"But probably everyone saw it apart from the referee.
"You are always disappointed if you lose it late on in the manner like that.
"But I am proud of the team today. It was a tough game.
"I felt it was maybe a matter of time before we got that second goal but at 1-0 there is always that little moment that can happen."
Asked if he had been lucky, Hill said: "Maybe. It could have gone either way and obviously at their place nine times out of 10 he might give it.
"It was a last-ditch attempt to try to get the ball. I don't know if I got it or not but we deserved a bit of luck over the course of the game."
With new boss Pedro Caixinha watching from the stand before he commences work at Ibrox on Monday, Hill knocked in from close range after Hoops goalkeeper Craig Gordon had parried an Emerson Hyndman drive.
He said: "To play in such a big game like the Old Firm is an achievement in itself but obviously to score such an important goal would be one of the highlights of my long career."
The draw did little material damage to Celtic who extended their lead over Aberdeen at the top of the table to 25 points and their unbeaten domestic run since to the start of the season to 35 games. They remain 33 points ahead of third-placed Rangers.
It was Graeme Murty's last game as interim manager before returning to take the Rangers under-20 side.
When he was asked about the penalty shout, Murty said: "Possibly. Rangers TV tell me it was an outstanding tackle but they're bound to say that.
"You get them and you don't get them. Things happen in the game and we've had some hard knocks.
"Celtic will no doubt say that it should have been but I'll just enjoy the moment if that's okay.
"I'm pleased for the players. I thought the players showed a degree of tenacity and grit that they have been questioned about and challenged about for a long time.
"They stood up in a difficult environment and managed to get something from the game. And I thought without two outstanding saves from Craig Gordon they could have had more.
"It took a real man's performance to go and play in that and stand up against a very good team and get something from the game."
Murty, who will meet Caixinha on Monday, gave the thumbs-up sign to the Rangers board at the end of the game.
He said: "It was just a little thank-you from me because I have had the honour and opportunity to go and stand on the sidelines at an Old Firm game.
"I'm incredibly proud of that but I'm also incredibly thankful to them for giving me that opportunity.
"I've just said to the players that I'm incredibly proud of the way they've worked and the way they've accepted me.
"That is something that when I've got a calmer moment and emotions are not swirling around I can reflect upon and use.
"We've got a good group of young players at Rangers and I'd like to see them progress through into that first team.
"My challenge now is to make sure they're ready for that step so this experience will only make me better for them."