Ethical behaviour is verifying the veracity of the claims rather than discounting them out of hand due to one's biases and when making counter claims backing them up with evidence.
I've had a decent number of conversations with persons I'm guessing you would describe as a "gater troll" as well as anti-Gamergate people. A small number of the former were raving loons who jumped on any conspiracy theory and used it to validate their own biases and prejudices, most however were thoughtful (if irreverent), disillusioned with the media and angry at being branded sexist/right-wing. One thing they were willing to do that anti-Gamergate people were largely unwilling or unable to do is to barrage me with evidence validating their claims (admittedly some were fairly weak, IMHO). anti-Gamergate people have largely pointed me to newspapers and blogs that uncritically present the claims of people saying that "Gamergate" targeted them, usually as part of a scaremongering, victimisation narrative about how dangerous a place the internet is, particularly for women. Reports often include comments about the police having been contacted and that an investigation being under-way. What happened to the standards of innocent until proven guilty or guilty beyond reasonable doubt? I appreciate that the persons who harassed Quinn, Wu and Sarkeesian might never be caught but is it reasonable to assert that one *knows* that "Gamergate" is responsible based on hear-say and conjecture?
A trend I find alarming is that simply asking for evidence results in claims that one is a misogynist or a Gamergate supporter. The very act of attempting to talk to a "gater troll" is that one is branded a "gater troll".
If the evidence is robust it should speak for itself. If instead all one can present is evidence-free assertions, ludicrously slanted opinion pieces, guilt by association finger pointing and goalpost shifting rhetoric then I'm afraid it is entirely unsurprising that a sceptical person would not be convinced of the robustness of claims made.