I knew I was different before puberty and was never attracted to females until long after I started my journey out of gay life.
Anecdotal evidence is all you have. There is no physiological difference between gay men and straight men. You are appealing to a physical reaction to stimulus, which in men happen when they get excited about cars, swimming in the nude even while alone, or any other activity that excites them. This is far from "empirical" evidence that homosexuality is innate.
Is Bob Davies your only example? How about Joe Dallas, Kominsky, and a multitude of others who were actively gay?