I think that many are as well, so I am basing my thoughts mainly on what I have seen on Youtube, where there have been cases where the racist was denying they were actually expressing racism by using plausible deniability, cases where it is just people calling people racist for stupid reasons and cases where the accusation seems stupid based off the clip but in the broader context of the discussion and the individual the accusation was justified.
I do have a personal experience of this in my previous job. I had a Kenyan colleague who is from the Kikuyu tribe. The nature of the jobs is serving customers with printing and other things. But he was helping a Zulu adult with printing and was getting gradually irritated because she was indecisive about what she wanted to do. Then he told her that he did not have time for her because other customers were waiting and told her to come back when she knows what she wants. She all of a sudden made a scene saying that he was being racist, which was totally the wrong reason. Those type of situations are what I am referring to. Irrational people making irrational statements to play the victim card.
I think what people are doing is looking at incidents in isolation without seeing the big picture. Maybe this lady was irrational and an idiot. Maybe she overreacted. An alternate explanation may be that she had repeatedly experienced racism in her past, and so interpreted the situation you describe in these terms.
We cannot read other people's minds, we can only read their actions. If an action reads racist to somebody, then is it really "irrational", as you say, to react to it in this way?
And also, we see here the primary of etiquette once again: That her outspoken reaction was deemed worse than any potential racism that might have had occurred; that the person who points out a potential problem is being read as the real problem in a given situation; that we immediately go on to defend a person from accusations before we even try to figure out what's actually going on.
EDIT:
Personally, I believe a lot of the hostile reactions to "wokeness" and CRT come from a place of insecurity and defensiveness; an attempt to protect one's self-image as a fundamentally decent person who would not possibly harm another human being.
I think in this, a lot of people make a mistake when talking about "racists" as people. Personally, I would argue that there are no "racists" - there are no people whose intrinsic being is one of being racist; rather, we have people intentially or unintentionally doing things that have racist effects.
In my opinion, our communcation about racism (not just us two, but people in general) generally suffers from the influence of the the two factors I've outlined above - the primacy of etiquette on one hand (which means that anybody who calls out racism is effectively painted as the villain of any given interaction), and our natural instincts to defend ourselves and the people we care about on the other (which means that people accused of racism immediately go on the defensive and stop even talking to the accuser, let alone considering their viewpoint).