In the 1940s-1950s, Hillary was open to the existence of Yetis. And he was responsible for some of the evidence noting it might be there in Nepal. In 1960, during his debunking Snowman expedition, which was a cover for a spy mission against the Chinese in Tibet, he had changed his mind. I would assume that, of course, after 1960, his “party line” would be there “is no evidence for its existence.” To say otherwise would be to contradict himself.