Oh, look. We still can’t beat United away. Or defend. And we have a shît keeper.

[IUFG]

Very odd it wasn't a yellow at least but scroll down here and you'll see the ref's view - can't really claim he didn't see it so no further action can be taken

https://www.bbc.com/sport/live/football/46464788

I think Fellaini disguised it from the ref quite well on second viewing