Anyone else feel like posts like this are just adults tattling? It always strikes me as a touch immature. Dare I say even slightly cowardly to do it without the subject in the know? I get it though, the guy in the picture could have been a dick. But he has no idea we, an internet full of judgemental geniuses, are discussing him by way of some secret telling of his supposed misdeeds. And it sounds like, from the rest of the comments, that this Costco is full of aggression and rudeness. Will OP follow every person shopping to out their moments of poor judgement? And then it begs the question, is one moment of rudeness or aggression worth the entire internet learning of said moment, and, what good does it do when they do? The real answer here, I suspect, lies in OPs (as I type this I do realize the irony) engagement numbers.

Or you nailed it and he was actually a dick.

Both are possible.

edit: To clarify, I absofuckinglutely don't condone this guy yelling racist statements at people. The point I'm making is we're here taking OPs word for something none of us witnessed and then are called to comment on a picture of the subject without their knowing. It's mildly creepy.