You seem to keep making a lot of assumptions about what happened, absent any evidence that it did. Why do you assume that she didn't make 'any attempt to talk to that Black employee's immediate coworkers'? Why do you assume she 'just talked to him'? Why do you assume there was no 'further investigation'?

We don't have any of this information. It's not fair to assume anything about whether they happened or not. Why are you making all of your assumptions in the direction of discrediting this individual? The article that is linked here links another article exposing a pervasive issue of gender and racial bias at this company, so it seems rather odd to be assuming that they had completely fixed this issue by the time of her hiring, a mere few months later, and that it was not at play in this situation. However, even if this article was not linked and this company was not specifically exposed for these issues, it seems odd to me to assume in the direction that research on bigotry in the workplace also does not support.

Why do you feel compelled to jump to the defense of someone you do not know, over an accusation which doesn't affect you and you have no stakes in nor any knowledge of the circumstances?