Like lots of others, you have the habit of leveling the "homophobia" charge when people disagree with you. But calling someone homophobic is not an argument--even in the cases where it's true. (And it's not--clearly not--in Miles' case). It's name calling.
The point is that there are probably unobserved characteristics of moms who take these kinds of drugs (as opposed to those who don't) that might have as much to say about the sexuality of children as the drugs themselves. Let's say, for example, that women who take diet pills are also more likely to have a psychological or personality type that is itself strongly correlated with raising gay kids. If you don't try and control for this characterisitic, the drug correlations are completely misleading. What looks like the effect of the drugs is really the effect of the personality type, or some combination of the two. It's a basic principle of the use of statistics.
Christian