I would say the 4th official did, the ref saw nothing wrong
Ref got a second chance and didn’t have the gonads to say what it was, clearly Bentancur does something that numerous players do every single corner, Burn lowers his arm and holds Bentancur, he knows exactly what he’s doing. He ends up falling on top of Bentancur.
It’s not a penalty in a million years and the refs bottled being correct, in favour of pleasing the fans.