I have been informed that I should have used "Hindi" and not "Hindu" to describe someone from South Asia. [sigh] Some people are easily offended, and will even refuse to believe that I had actually meant to type "Hindi".
Actually, neither term describes a nationality or ethnic group. Hindu is a religion; Hindi (also called Hindustani) is a language.
Of course, you could always have said "dot Indian, not feather Indian."