It's not so much that the NBA thing isn't some sort of racism (though, I'd disagree with that, just like I disagree with calling a player black automatically means the person is racist), it's looking for examples in other sports to take away the focus from what happened today (I didn't read through the whole thread so apologies if you didn't start this comparison). It's classic whataboutism that's often prevalent when people are trying to defend or excuse moments like this. Context does matter, and this was not the setting for an official, not a player competing with another player (like in the comparison with Luka), but an actual official put in place to keep the integrity of the game among other things, this wasn't the setting for him to use someone's skin color to describe them. You can point, you can walk over to the person, there's a myriad of ways you can go about it without resorting to using their skin color.
And the NBA thing is far worse in the language, but it's par for the course in the NBA. The thing that a lot of ignorant people (usually on the white side) seem to forget is that there is a double-standard in place. They might not like it, but it's far less egregious for a black man to call a white man white boy/man than a white man calling a black man black/boy. You have to accept that historical context have created this double-standard. To try to constantly go back to some of the discrepancies as if the world has always been equal and so therefore every racial moments should be judged exactly the same way whether the target was black or white is ignorant at best, and sadly it's not a very original or sound argument. If you have a problem with this double-standard, then you should have an even bigger problem with the systematic racism some black people are put through whether it's in their living conditions, education, social injustices, etc....but often times the people making the kind of argument you did see only the double-standard that affects them on such a minor, insignificant scale (like being called a white boy or not being able to say the word 'nigga') and sweep under the carpet the overwhelming impact the double-standard has the other way and how it affects black people on far more than just a sports venue, where their very lives can be in danger.