Logically, if that happened to my child, my first assumption isn't that my child was purposefully snubbed. It's that these characters can hardly see in the costume and they are moving through the crowd along a parade route rather quickly. It looked to me like the character waved at them. I think it's highly plausible the character didn't intentionally snub them.
Is there evidence of a pattern of that type of behavior?
At this point, I'm just waiting for the demographics in this country to change and its my sincere hope that white folks keep that same energy when they are the minorities. My common sense knows otherwise though.