No, I’m not misinterpreting caution for denial.
People believe racism to be monstrously bad. Therefore they don’t want to accuse someone or racism without having a very high standard of proof, just like you wouldn’t call someone a child abuser or a murderer unless you were really sure. Because of that, they don’t recognize the obvious fact that people of colour are treated differently than white people every day.
To say that race was likely a factor in this is not to say the person who kicked her out of the mall was a member of the KKK.
I’ll use the example of “carding” (or non-investigative public/police interactions where personal information is collected, as my police would prefer I call it). The rate at which it targets black over white people is staggering. That’s a situation where police are making a snap decision about whether a person is suspicious based on how they look, and where I live it’s about three times as likely to happen to you if you are black (I get the sense it’s a lot higher in other places). It also makes up a lot more police/public interactions than arrests for murder do. So if a black person is stopped by police, without knowing anything about the circumstances, I should assume that race was a factor because that is more likely than it not being a factor. That’s different than saying that every cop should lose their job.
So I’m not mistaking caution for denial. Undue caution is denial. It’s not denial of racism in that particular incident (where racism may or may not have occurred) but it’s a denial of the prevalence of race-based judgments in society, which is a denial of the experience of people of colour in favour of the theories of white people.