You speculated about the motive of the harassers, not the actual chain of events. Nothing you say here says that the harassers attacked her for being a woman instead of attacking her for cheating the game review system.
> instead of attacking her for cheating the game review system.
Again, he never reviewed any of her games, so unless your argument is that no game journalist should ever date any game developer under any circumstances, what system was she cheating exactly?
For example, lets say a twitter mob attacks a man for something he didn't do. Is that misandry? No, they did it thinking he actually did it.
Why does it matter so much to you whether or not 60%, or 59% of the people engaging in the harassment were sexist?
It is still bad, regardless if we get the literal exact percentage correctly of precisely how sexist each individual was.