To me, they key point is that "Kelly" did not apologize.

I'll agree. Mistakes can be made in the moment, but they're worse if they aren't corrected after some reflection.

That said, there are circumstances where a person with dark skin tone is hard to see.

My wife is darker than the author seems to be, based on her photo. At night, if she's (my wife) wearing dark clothes and comes out of a dark room unexpectedly...well, we'll say that she has startled me a few times. Several circumstances have to come together at the same time for that to happen that I don't usually associate with sitting in a conference room for a meeting, though. So while the statement's true, it's hard to imagine a work situation that it'd apply to.