The officer spotted an incongruity based on his experience. Skin color may have been part of the pattern of incongruity.

Dress could also have been such. If you saw an unwashed person wrapped in a blanket at the wheel of a shiny sports car I think you'd be inclined to call the cops.

Pattern recognition. Thats all it is.

Legislation that requires portions of patterns to be disregarded reduce effectiveness of the technique.

Stopping them to point out a damaged light is OK. Should be done regardless of pattern. It raised a new pattern - people who refuse to stop or run are usually lawbreakers (and reflexively - become lawbreakers by refusing to stop).

PC BS - thats what it is.