Just had a look at the McArthur foul on Saka. It was a deliberate kick. It doesn’t, IMO, even register as a late or poor challenge because he wasn’t in a position to challenge for the ball without going through Saka.
I suffered a broken fibula from a less severe kick than that, when I was 17 years old, when my weight was fully on my left leg - ref didn’t even give me a free kick - and to put it into context had Saka’s foot been unable to lift from the turf, during the contact, he too could have ended up with a broken fibula.
I know red cards can be reduced to yellow, post match. Does it work the other way, or does the failure of the VAR officials to bring it to the match ref’s attention mean the end of it?