Here in the U.S. we have "African-Americans" who know they're Black, refer to themselves as Black, and are, indeed, Black, yet they take offense at being referred to as such. We also have illegal aliens from Mexico who know they're Mexican, refer to themselves as Mexicans, and are not only illegal but certainly are Mexican. Many of them take offense as being referred to as Mexicans. Unfortunately, we non-Hispanics have difficulty distinguishing between Mexicans, Guatemalans, Colombians, ... etc.

It's all in how you see them. If you "see" them as just another "***-can" then it's likely to be taken as an offense, as that's a definition rather than a characteristic. Often it depends merely on how you meant it, because that shows, no matter how subtle you try to be.

Such characteristics are not a definition of the person ... unless you make it so.

RE