If you look at each episode in isolation, both Cahill and Kelly fouled Martial when he was 1v1 with the GK, and so both could have received reds.
Miljahovic's foul on McTominay for the pen would have been a yellow 10 out of 10 times if it happened in the middle of the pitch, and I don't see how it makes sense for it not to be a yellow when it instead happens in the box. It is still sabotage, it just happens in a more dangerous area of the pitch. And so, he could have received his second yellow.
There was also Zaha's foul on Pogba before our goal. I can see that it would be difficult for the ref to give him the second yellow after we scored, but if anything else had happened I think he would have got it. And it doesn't really make sense that us scoring should save him.
So that's four times Palace players could have received the red card. I think the only reason they received none, were because there were circumstances that would require some spine from the ref to give them.
Unfortunately he didn't have one.