Don't know what your talking about.
I have a good friend from Iran, and he is mistaken for a Mexican *all* the time. As a matter of fact, he conducts civil and criminal investigations and he is used in predominantly Mexican areas since he blends in so well.
We went to CA two weeks after 9/11. I would see dark skinned, brown haired people and would be able to id many of them as hispanic but then there were others that I really couldn't figure out if they were hispanic or middle eastern. I'm probably not the only American that can't id differnet groups of people.