The rule doesn't mention intent from what I see. It is all about endangering an opponent whether you mean it or not. Not sure he does that as the follow through doesn't make contact despite there being no evasive movement from the opponent. Trying to look at all the angles, the one that looks bad sees Ryan touch the ball when The Rangers player is a good yard away. By the time he slides through the player is past the action and out of the way of the follow through. You can't endanger the player when he can't be caught by the movement of the defender. His fake stumble after the tackle was the only thing that endangered him and could easily have been a booking. Imo it is a defender going in strong and an attacker not fancying it. The ref basically did what biased Scottish refs do. Give the advantage where possible to the The Thes particularly with 50 odd thousand shouting and an unchallenged narrative of Porteous is a thug. whether the refs are intentionally biased and corrupt might be up for debate but Scottish football is completely corrupt allowing The Uglies to ban away fans and having referees almost exclusively from the west of Scotland.
I'm really disappointed in Jack Ross. He should be publicly standing up for Porteous especially the way Gerrard has went after him. The same Gerrard who really was a nasty piece of dirt on the fitba field. Ross is without doubt an honest guy giving his opinion but he must see how successful Gerrard is in playing the victim card with Morelos and making out Porteous is a thug. I'm a bit fed up with us constantly playing with a straight bat when others are driving nails in theirs and playing dirty.