Ex-referee Dermot Gallagher insists Alistair Johnston's block in the box against Kilmarnock "can't be a penalty".
The ball hit the Canada international on the goal-line after Killie full-back Corrie Ndaba thought he had scored.
And while some, such as Kris Boyd, thought it was a penalty, Gallagher feels that the referee made the correct decision.
Speaking on Sky Sports' Ref Watch, he said: "This is the one that triggers it. It hits his arm. No doubt about it but it is breaking his fall. It can't be a hand ball.
"If that was a forward and he managed to poke it into the net it would be disallowed. You think it is unfair but that is how it is.
"We've got what we've got."
Meanwhile, Celtic hero Pat Bonner has picked out three players that struggled during the defeat to Kilmarnock.
The Scottish champions lost 2-1 at Rugby Park as their gap at the top of the table was reduced to five points.
And while Bonner felt the whole team played poorly, he picked out three players that have to do more going forward.
Speaking on BBC Sportsound, he said: "Celtic looked really uncomfortable and they just couldn’t pass through the midfield. Even getting the ball wider at times they just couldn’t get a hold of it.
“Young Mikey Johnston kept running towards the ball. He was outmuscled and that then stopped Celtic from from getting a hold of the ball.
“Palma didn’t really contribute in the second half. Oh was always on the halfway line and he had a couple of good moments where he held the ball up and he turned and he played in Matt O’Riley but it was all too few from that perspective.”
