That is where the referee should just report it

And let the FA handle it from there.

Fellaini should have been gone regardless, but that kind of 'embellishment' puts the official in a terrible position. Because it isn't truly a dive, nor simulation. Just silly exaggeration.

Not to mention I believe simulation can only be called during the run of play - so if you book him there, it has to be for 'misconduct' which has its own set of standards.

edit: I'm going to correct myself. He can be booked for unsporting behavior there - 'shows a lack of respect for the game'. Works for me. The line that allows for a caution for simulation deliberately uses the word 'foul' and what Fellaini did was not a foul.