That is not at all the same. Saying that Yagan supports oppressing gays because he donated to Cannon is like saying most of us support the PATRIOT Act because we voted for Obama. Eich donated to a campaign whose sole purpose was to take existing rights away from gays in California.
It might not be 100% the same, but it's also not completely different. You don't get to pick; if Yagan honestly was against gay discrimination, he shouldn't have supported Cannon. Especially since by 2004, the year of his donation, it was already evident that Cannon was against gay rights.
But this is not what I'm trying to say at all. Merely that: If OKC wanted to speak out against Eich, they should've done sone in a mature and careful way - it's what a decent person (be it legal or nature) needs to do anyway, and even more so since rarely one is without fault.