I don't think his being a minister had anything to do with it. They met at a Black funciton, not a religious function. However, as a Senator who promised to help her in various ways, that does put him in some sort of authority. On the flip side, she may have appeared mature for her age, since she was already in University.

"Ms. M was a university student in Ottawa at the time of the affair while her parents lived overseas. She was 16 when she met Mr. Meredith at a Black History function."