This is actually true. This entire thread is "racial", as it pertains to race. Maybe the confusion here is that it's implied by everything that you've said that OP's use of the descriptor "black" about his work friend would be "racist".
I get your argument/point that using the racial or skin-color descriptors in a text setting implies something about the speaker, but even if that is proven to be true (saying it's proven/true, by the way, don't make it so) it doesn't make them racist and it certainly doesn't tell you anything definitive about them. Maybe they're a visual person and they describe things based on what they see....maybe in the context of the conversation it is relevant.
It is true that not all racial statements are racist.
A racial police statement describing a suspect is by function and necessity, and it is not racist.
When race is applied in a statement where the only rational reason why it is applied is to imply something about the race... is not merely "racial", it is by definition, racist. Either that, or the speaker is non-fluent or simply less educated.
I have already explained my view on Racism, I believe it is damaging but I don't condemn it wholly, nor do I profess to be a saint about it.
Also, a person can believe that people of different races are different without being racist, particularly if you don't think their race is the cause of those differences.
If you believe that race is a subset of another factor - such as culture or economics, then this is a reasonable assertion.
The truth is, that is not the case in general. If you say because culturally, more gang violence tends towards Blacks and Latinos, then you believe that Blacks and Latinos are different, you somehow get out of racist.
That is a specious line of thinking. Attributing culture to race, rather than the other way around, is not any less a direct reflection on the race.
This is your line of logic:
I do not like Gangbangers.
Gangbangers tend to be Latinos.
I therefore avoid Latinos and I am therefore not racist because it is not a factor of their race but the culture that predominates the race
Versus
I do not like Latinos
Because Latinos are all Gangbangers
I therefore avoid Latinos
In either example, you are avoiding Latinos. Whether or not you believe that most Gangbangers are Latinos or most Latinos are Gangbangers becomes a fairly irrelevant point.
You believe that "people of different races are different". but "race is not the cause of the differences"
Of course, being Latino does not cause one to be a Gangbanger. But you knew that already.
So what is it is about Latinos that make them different as a race?
It is a specious and illogical line of reasoning. I would like to hear your example of a case where "people of different races are different but race is not the cause of the differences"