If the aerial tackle had been against Wasps, or the 'looked at' tackle later in the game, both would have been unpunished by the ref, ignored by Graham Hughes, and followed by a retrospective red. Seriously for a moment, there were so many unpunished incidents by Premiership standards in the match. Tricky for the ref, but I do not expect citngs after such a match as this.
I think the ref was under intolerable pressure, Erasmus should have been banned from the stadium for his ludicrous midweek tirade. Frankly, the ref bottled the aerial tackle, which was a likely red, and the afters worth a yellow based on rhe ref's prior warnings to both teams. Either red, or yellow, yellow, the result would have been the same- one player off. He was not going to send a player off for the sort of reds we have seen all year.