(1) To you, is a person being white in a white majority country sufficient for you to suspect him of being a beneficiary of white privilege?
Yes. I am that person and have been an unwitting beneficiary of white privilege for most of my life, and I see it operating to the benefit of every white person I know.
(2) I went to a big name university that practices legacy admissions, and I'm a legacy. Is that sufficient for you to suspect me of being a beneficiary of legacy admissions?
Yes. No way to be absolutely sure, but … my father went to Yale, was a star rower for them back in the day. So my older brother got in, no questions asked and graduated magma cum laude. I dropped out of high school, but found out later that I had been offered an entry path to Yale WITHOUT SO MUCH AS A GED. No other qualifications than family member alumni.
I wonder how many black or Hispanics were offered any such thing … even as legacy applicants.
But to your question - YES.