Maybe they were brothers.
You can show how unlikely and improbable these stories are, but somebody is always going to say that if there's even the slightest possibility that they are true, they must be true. You can say how unlikely it is that when Pierre and Margaret snuck off to an undisclosed island to be alone on their honeymoon, that the island had to be Cuba, but some people are going to believe it anyway.
The story that Pierre Trudeau was homosexual is nonsense. He was with another woman after he divorced Margaret and had a daughter with her. He also dated a lot of women before and during his marriage, Kim Cattral, Margot Kidder, etc. But some people are going to believe that he was gay whatever you tell them. It's like believing or saying that Michelle Obama is a man. Some people just have to believe it (or say it).