Honestly he's never made any impassioned rants on the subject, never spoken out against gay marriage, never reportedly acted out against any homosexuals in any way. He only made one small donation to what was, at the time, a very popular political campaign.
Maybe he was misguided, or misunderstood the reality of what Proposition 8 would mean. The campaigns were certainly filled with misinformation that suckered in a huge number of Californians. I know we technophiles like to think we're cut from a better cloth than that, but there are days we're just as gullible as the next.
We're all guilty of lapses of morality at some point in our lives. Hopefully we learn from those mistakes. Hopefully Brendan will, as well.