Cav is a ******. It's part of the territory. When he wins, he shoves it in your face. When he loses, he shoves it in your face. He deserves to be called out as a ******. Feillu's point is that Cav is a ******. Is he as much of one as Riccò? Probably not yet (Feillu made sure to take doping out of the equation, but Riccò the personality rubbed people up the wrong way enough for Bram Tankink to punch him out back in '08), but he's certainly got more than enough history of calling people out, whining whenever he loses.
Being the best is great and all, but it does seem that Cav has got to the stage where you feel you have a god-given right to win. He doesn't have a right to win - he still has to compete with people. People who he is better than - but that means they HAVE to try other things to beat him.
Think of it this way. If I go into battle with less men and less firepower than you, I will lose, assuming all else is equal. But if I change the territory of the fight to suit me, try unorthodox tactics (and yes, possibly ones of dubious moral nature) I have more chance of winning. If I then win the battle and go home, am I treated as scum for acting underhandedly? No, I'm lauded as a hero.
The more Cav proves himself the best in a straight sprint, the more people will be determined not to take it to a straight sprint, because they can't win in that case. And that means the more times Cav has to deal with somebody doing something other than just letting him waltz to victory. And so far he's shown that his way of dealing with that is to whine.
Besides, Cav always loses the first sprint of a GT then comes back to win every single other one, so who cares? Every flat stage from here on in will be an HTC procession.
And as for Romain Feillu saying that he would try and box Cavendish in?
If Feillu gets close enough to Cavendish to do it, something's gone very wrong with Cav's leadout.