His intention was to kick Gomes and bring him down for the elbow. If you go in on someone like that the risk of injury is not negligible and he should face 100% of the blame of the consequences.
You guys are talking about it as if Son just accidentally hit him while jumping or striking the ball - he intentionally tried to avenge himself and when you do something like this you have to accept that you're responsible for the outcome.
Spot on. Had it been a normal challenge for the ball, I would have agreed with the posters who say no red.
However, in this case the tackle is only a minute or two after the elbow incident. From watching the video a few posts above, it is clear that Son had no chance to get the ball, yet he still went all in on a sliding tackle at Gomes’ feet from behind. In light of the prior elbow incident I am not in doubt that Son was out to get some sort of revenge, though of course not intending the actual outcome.
When a tackle is clearly malicious, such as in this case, you have a better case for considering the outcome when deciding on which card to give out (if any). In normal tackles, a player is mostly out to get the ball, and normally has a good intent with the tackle. The player should then primarily be judged on the tackle and not on the result. However, when there is a lack of good intent in the tackle, it is a different situation and the player needs to take the consequences of the results of his misdeed, as there was no excuse for making the tackle in the first place.
On another note, for those that say that this was just a run of the mill sliding tackle - it is clear from the video that tackling from behind at full speed, while Aurier is at the same time bombing into the situation from a different angle, is clearly a dangerous thing to do. Such a tackle will often take away the legs and the balance of the player running with the ball, and personally I can not think of many scenarios on a football pitch that is more dangerous than to be sliding through the grass out of balance, with your legs kicked away under you, while 80 kilos of granite is lounging at you at full speed from the opposite direction. This is what happened here, and by doing this reckless and illegal tackle, Son sent Gomes directly into Aurier’s tackle. I would myself much rather hit a goalpost. The fact that Son did not make these considerations before making the tackle is on him, he can not miss Aurier coming into the situation. Of course it is still harsh to give Son the full blame of the actual outcome, but is this reckless endangerment and a red card? Yes, every day of the week.