Pundits Chris Iwelumo and Shelley Kerr were in agreement that Nir Bitton deserved a red card against Dundee United.
With Celtic pushing for a winner, the midfielder received his second booking from referee Euan Anderson for a shove on Declan Glass.
Having already been shown a yellow for professional foul on Tony Watt the whistler was left in little doubt over the decision - though many fans felt a foul on Greg Taylor in the build-up had been missed.
It leaves Ange Postecoglou without a derby day veteran heading into the top of the table clash with Rangers.
The Sportscene pundits struggled to find a defence for the 30-year-old with a crucial game coming up on Wednesday.
Iwelumo said: "The first one is standard. He had to make the challenge with United on the break.
"Celtic had bodies trying to get back, and it's understandable. He accepts this one.
"Tony Watt isn't really going anywhere, but there are bodies in front of him.
"This (the second) is the one I can't understand.
"You want to keep everyone on, and yes Declan Glass is getting away, but he is covered.
"He does not need to put hands on the back of Declan Glass there.
Kerr added: "I think initially it's a short pass to Greg Taylor, and he's on the inside of the pitch so he is on his weaker side.
"He is wanting to play it and they get caught. There is no doubt that it's two yellows and it merited a red.
"I don't think there is any argument there for Nir Bitton."
