I think it's a case of his family keeping secrets from him.


http://www.thedailybeast.com/articles/2014/07/01/world-cup-anchor-mike-tirico-s-bizarre-history-reports-of-stalking-and-sexual-harassment.html

According to a 1990 profile of Tirico in the Syracuse Post-Standard, “because of his dark skin and ethnic features, Tirico says, most people assume he’s black. But he’s seen pictures of his father, his father’s mother, and his father’s sister, all of whom are white.”