I don't think Crowder's behavior is racist at all. I think though he let his insecurities get to him and fired back with the race card, which was an overreaction.
It is 1000% clear that Durant is a far better player than Hayward. Crowder for that reason was glad to recruit him. To many of us and to many NBA analysts, it is also obvious that Hayward is a better player than Crowder, but not by a large amount. What Hayward does that Crowder cannot do is create his own shot and shots for others, and he is a superior ball handler. Crowder has him matched or beat at every other aspect. The thing is, Crowder gets a lot of his offense from our system, whereas Hayward creates most of his offense.
To us, these differences are obvious. When you are an NBA player however, you generally tend to think more of yourself than the media does, and it is only natural for Crowder to think that he is as good or better than Hayward. He's also likely worried about getting his big payday while he is still producing at a high level and getting minutes. These insecurities likely caused him to overreact and take a shot at fans using the race card. His mind had to reach for something to justify to himself why so many people are sure that Hayward is clearly an upgrade over him. I can't blame him.