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?

All the best workplaces that don't have a racism problem are the ones where lightly suggesting diversity training is met with hostility, denial, and sacking of the person suggesting it. Such actions really highlight how seriously said company takes concerns of bigotry at the workplace and proves they're giving it their all to make it as inclusive as possible.

I’m siding with the employee who was treated like a racist

Proving how incredibly not racist I am by taking incredible, personal offense at the suggestion of checking possible biases I may have as manager at a company with a history of racial biases, because I care about combating racism just that much

This isn't great though:

Notably, Alm was hired at Bungie just five months following an IGN report on the company’s work culture. In it, over 25 employees alleged the company had a history of allowing toxic culture to fester, including racial and gender bias, with those who reported such instances to HR alleging their reports were frequently dismissed or even turned against them. Following this report and prior to Alm’s hiring, Bungie’s former HR head stepped down from her role. IGN understands from its sources that following its 2021 report, Bungie also hired a number of new HR personnel in an effort to address the issues from the article, amid some pressure from its new parent company Sony.

I’m siding with the employee who was treated like a racist because one person who may have been underperforming said he was without any further investigation.

It's so poignant that you tell on yourself with this statement.