Then start by being angry at Eric: the man who calls for all men, logically including those like him, to be murdered!
I have no idea who Eric is, but the woman who first brought up this whole thing has indeed joked with "Kill all men." Very clearly joked. Are you seriously using that as an attack? Because that's... pretty darn hilarious, actually.
It's like when I got called a eugenicist for doing a joke bit pretending to be an old-timey scientist. For someone so adamantly defending an offensive piece of humor, you really should pay more attention to what is and isn't serious!
No, sadly the woman who brought up this whole thing wasn't joking. She is a manhater/misandrist. She has verified this as clear as day several times because indeed most peoples initial reaction is "surely this is a joke?".
The character of the person who wrote the complaint doesn't have any relevance regarding whether the joke in the game was okay or not. It wouldn’t make the joke any better or worse if Hitler himself complained about it.