The big calls from Rangers' 3-3 draw with Celtic have been assessed by a refereeing expert.

Dermot Gallagher, a former official in the Premier League, has analysed all of the major incidents from yesterday's pulsating game. 

Speaking on Sky Sports' Ref Watch this morning, he went through each instance one by one alongside his fellow panelists, including Stephen Warnock and Sue Smith.

Celtic penalty - Connor Goldson handball

Gallagher said: "It's a good intervention. The referee can't see it on the field. You see here, he lifts his arm up and puts it towards the ball. There's no doubt in my mind.

"John Beaton goes to the screen, sees it, comes back, and simulates exactly what he did by showing that it taps him on the elbow."

Warnock added: "He's thinking he's going to have someone coming in the challenge him, so he's trying to protect himself. It's similar to the Dan Burn one before - when you jump, you don't jump with your arms by your side, you always jump with a physical aspect, thinking there's going to be contact from somewhere. Listen, though, he's made an error and he's been caught."

Smith: "I wonder is he trying to keep his arm tucked in? I think because of the position his arm was in, it was always going to be given. Sometimes defenders are defending differently now in terms of their arm positions because they're worried about things being given."

Foul - Alistair Johnston on Fabio Silva

Gallagher: "This was a really, really interesting situation because has he been punched in the face? I think Alistair Johnston has put his hands up to block him off. He knows there's going to be a collision, he raises his arms, almost to brace himself, but he certainly doesn't commit an act of violent conduct."

Rangers penalty - Johnston on Silva

Gallagher: "This is a very interesting clip. He [Silva] gets a yellow card for simulation, but when you see it again, obviously the angle you see Alistair Johnston lifts his leg, catches him on the knee and it's a penalty. 

"So, the referee then has an even bigger dilemma because of the pressure he's put under. He goes to the screen, he comes back, the yellow for simulation is overturned, he gives a penalty but then it ramps up because the Rangers players are saying 'Johnston has already had a yellow card, he should get a second one'.

"For me, it's a foul. It's not a second yellow card, so it's not a red. He goes to the screen and he's got all options, so he can yellow card him, but I don't think it's a yellow card challenge. I think it's a foul."

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Warnock: "I think it's a good decision. That's where we want VAR to step in."

Smith: "Yeah, completely agree. Initially, you can see why the referee thinks he's gone down too easily, but then you can clearly see when he goes over to the screen, you can see the connection and that it's a 100 percent penalty."

Gallagher came back in: "The only thing there is you've got a complete pendulum swing. You've gone from the referee giving no foul and a yellow card for simulation to going the other way, it's a penalty. 

"If he'd then gone penalty, second yellow, red card, that would be such a massive swing. You can imagine the swing if he did."

Disallowed Rangers goal - Foul in APP (Attacking Phase of Play)

Gallagher said: "Well, they travel a long way. They (Celtic) have a lot of time to re-set. I know they don't get the ball back, but the referee goes to the screen and gives a foul. I don't think there's any doubt it's a foul, but it's whether the foul is in the immediate build-up. Is that foul in the attacking phase? VAR felt it was, sends John Beaton to the screen for the third time in the match. I don't think we'll argue it's a foul, but is it re-refereeing?"

Warnock: "That's the problem, the re-refereeing of the game, I think that's the hard bit to understand."