Shizuku: "This thread is a masterclass in whataboutery."
Let me quote Wikipedia's definition:
"Whataboutism, also known as whataboutery, is a variant of the tu quoque logical fallacy that attempts to discredit an opponent's position by charging them with hypocrisy without directly refuting or disproving their argument."
en.wikipedia.org/wiki/Whataboutism
First thing I would note, is that you didn't actually give an argument in the opening post. I don't see that anyone "failed to refute" your argument, or tried to "divert from" your argument, when you didn't actually give an argument in the first place!
Can you identify the fallacy here when you didn't give a real argument to start with?
Rather, I think people were left to guess about your intentions; and they guessed you were using this story to bash on the GC ideological position or movement. But then in that context, where is the fallacy in pointing out the behaviour of the other side?
If there was a widespread violence problem in the GC movement, then sure, pointing out the behaviour of the other side (even if equally bad or worse) would be a diversion in a way.
But I don't see a problem in pointing out that this is a rare incident on the GC side, condemning the rare incident, and also pointing out the worse behaviour of the other side. That seems reasonable in a context where we are left to guess about your exact intentions, but that they are presumably hostile.
Not all use of "tu quoque" amounts to a fallacy. It depends on the context. If you're trying to discredit the GC position just because someone did something bad in its name, then "tu quoque" is a fair response here.