Has he been banned?
As I saw it, Porteous was hanging on to Mara and shoving him as they jogged along, Mara responded with a weak smack/push in the back.
The defender went down dramatically as if assaulted with a baseball bat, the keeper, who himself recovered from the career-ending injury in the same match, ran around trying to get a red card for Mara.
The defender then got up because his play-acting hadn't worked - and perhaps realising that simulation when you are already on a yellow is asking for trouble.
It looked like handbags to me.