It's text book SFP imo. Did he lunge? yes. Was it from behind? yes. Was the players safety endangered? yes.Sorry but I'm still siding with its not a red card, it's a freek injury which 9 times out of 10 would not occurred I shall bet.
It was reckless at worst so maybe a yellow card would suffice. If Andy Madley thinks it's a red because of the force and not of the outcome to Elliot then fair enough but how can we know that for sure?
I just think the Son one was much much worse but got overturned because the injury was not caused by the tackle yet he tackled from behind with the ball miles away because he was annoyed he did not get a free kick before hand. This was a genuine attempt for the ball which he got and the contact/injury occurred after getting the ball. There's no consistency and Leeds fans have every right to feel aggrieved.
Any player who lunges at an opponent in challenging for the ball from the
front, from the side or from behind using one or both legs, with excessive force
or endangers the safety of an opponent is guilty of serious foul play.
The fact it was an "freak injury" is not a consideration, it was a direct consequence of the players action. Accident or not, this is a red card offence, it ticks all of the boxes.
2 other buzz words I'd chuck in, not in law, are airborne and out of control. At the point of the challenge both feet are off the ground, this results in a loss of control meaning the player cannot avoid making contact and thus injuring/endangering his opponent.
A freak injury is like Djibril Cisse leg break whose leg just snapped whilst running.