As a non-native English speaker living in a predominantly white population, it's becoming more and more of a minefield of what can you call or identify someone by. As far as I was aware there is no negative connotation to word black, right? It's slightly worrying in my opinion that you can't describe someone by their most recognizable physical feature. As Webo was a black man surrounded by a bunch of white men, I would've picked up that characteristic first as well and if I'd had to quickly single him out which one of those men he was, being black is by far the most quickly recognizable. I'd understand the offence better, if the physical characteristic was something widely perceived as negative, e.g. fat, ugly etc., but there is nothing negative about being black.
You could say that he could've pointed to him but I'd like to say that in my country (Estonia) it's rude to point at someone, using your index finger, anyway. Nobody would make a big deal out of it, but just to show, cultures are different and you can't take it all into account when making a quick decision.
I really feel sorry for referee. The man has probably lived in Romania most of his life, which is predominantly white country as well. It's probably normal there (I only assume this, because it's how it is here) to refer to someone dark-skinned as "that black guy". Because being black there (and here) is very rare. So he was talking to his compatriot, referring to Webo as "the black guy" in his native language. All of a sudden he's branded as a racist all over the world, in newspapers, in social media etc., while I'm 99% sure there was no malicious intent behind it whatsoever.
Now that I've written it, I realize that it sounds like one of those "Not to be racist, but..." posts, but I guess I'll post it anyway.