I mean, is stating anything negative but based on statistical evidence about a race racist?

Yes. Chalking up anything to race is racist. Making broad generalizations about all people of a specific ethnicity or skin tone based off of a minute data point is racist.

For example, if you add a single filter to that data, such as controlling for only people classified as Middle class, the numbers even out.

In truth, ethnicity has little to do with whether someone is prone to violence, the conditions of their childhood does. You'll find that crime rates among all ethnicities who live near or below the poverty line to be higher than average. The reason it seems like Black people are disproportionately involved in violent crime is because they are disproportionately affected by poverty.