It sounded like everton were singing "dirty korean b******" .

Why is it that Son was initially booked, but when the ref saw the extent of the injury he changed it to a red?
Obviously Son didn't mean to injure him, so if the ref thought it was just a booking does it matter that he was badly injured?
What if the lad had landed on his head and died, would Son have been to blame?

*By the way, I have every sympathy for Gomes, as I would for anyone injured in this way, and wish him a full and speedy recovery.

Apparently this is the decision as verified by the PL:

After the game, the Premier League released a statement explaining why the colour of the card had been upgraded.

It read: "The red card for Son was for endangering the safety of a player which happened as a consequence of his initial challenge."

All of the 'experts', from MOTD to ex Referees, all seem to agree that Son should not be penalised for consequences that occurred after the challenge, but only for the challenge itself - a yellow, and that anything else is a whole new interpretation of the Laws.

Tottenham are going to appeal according to the newpapers.

A stairway to Heaven and a Highway to Hell give some indication of expected traffic numbers

As a side note, someone should take Richalison (?) aside and tell him that is a proper reason to go down and stay there, not a little nudge to the side of your face.

Red card overturned.
Quite right too imo.