It isn't "concern trolling" or "white knighting" to call out racism or bigotry, and expect some decency in the discussion. If it is "exhausting" for you to be propagating unfair stereotypes, perhaps stop your bad behavior?

Your comment assumes, a priori, that the stereotypes are in fact "unfair". I don't know enough about cybercrime rates per capita amongst Eastern Europeans vs. other populations to be able to say if it is actually an unfair stereotype, but it is an indisputable fact (supported by virtually every jurisdiction that tracks crime rates by things like national origin, ethnicity, etc.) that there are population level differences in crime rates.

I don't think a person saying Eastern European are observed doing something more than expected is inherently racist. It is a claim he either does or doesn't have evidence for.

If he made the claim with insufficient evidence or made the claim in contradiction of the evidence, then it becomes racist, but I don't think making the observation and doing the calculation is the racist part. It is a simple chi-squared goodness-of-fit test.