It could just be an innocent case of ignorance on his part: maybe Russia just doesn't have a history of comparing blacks to apes/monkeys in a racist way, and he didn't fully understand the implications of calling a black guy a gorilla.

Remember, Muhammad Ali called Joe Frazier a gorilla. It wasn't a racial thing, he wanted to insult Joe by insinuating that he was ugly and primitive. It's highly probable that Kovalev was doing the same thing just to get under Stevenson's skin, a little harmless gamesmanship, and didn't realize that people would be uncomfortable with a white guy calling a black guy that. And let's be honest, if you take away the whole racial angle... Adonis does look somewhat ape-like. There, I said it.

This is what I hate about our current culture: we automatically jump to conclusions and think the worst about each other instead of stepping back and seeing if there is a less damaging, more reasonable explanation.