Don't agree mate. You're saying that because of one game. First, he didn't get Son sent off, Sonny did that on his own. R might have overreacted but so does everyone, all of ours included.
Then there's the monkeying/booing thing. In all probability he made a mistake, he misheard, but it's something that's unfortunately uppermost in all black players minds. There was a similar case when Rahim Sterling (?) thought a Chelsea fan had called him a "black cunt" when it (apparently) turned out that the chav in question had said "Manc cunt". I wouldn't blame either Sterling or Rudiger, maybe they should have accepted that they may have misheard, but hey ho, I don't think it makes either of them "cunts".
Of course, it doesn't make that part of the Park Lane end or the chav racist, but like I say, unfortunately, these are the times we live in. What I am saying is that I don't think either were malicious in their accusations.
As a player, I'm not saying we should sign him (I'd rather not sign anyone from Arsen@l or Chelsea really). I do think he's a very decent right back and streets ahead of what we have though.