I believe so. Of course, if you asked the attendant, she probably would say that she was annoyed by XYZ thing that you did, although she would not have the awareness to know that you being black created the annoyance, as in, if a white person did the same as you, she wouldn't be annoyed. This has happened to me a lot. That people just think, "Oh, her tone was annoying," "Or she just didn't clarify enough," but what is veiled in their annoyance is something they might never recognize. They actually think it was YOU that created the annoyance, and not their own prejudices.