Very few of the refs thought that the red was an obvious mistake, most thought that it could have been yellow or red and that neither would be wrong - not the sort of thing that would have been over-turned by a video ref and that is what is being discussed here. Same with the Ramirez card.
Think you might be clutching at straws there. Many refs would have sent Stephens off and the decision certainly wouldn't have been over-turned by a video ref. Have a look here for a dicussion among a group of referees about the incident.
I know it's an article of faith on NSC that The Complete...