Jon Pretty sounds like a complete creep and yes, based on this account, a predator. That being said, there is a court and criminal justice system for a reason. While I empathize with the author, and utterly despise the archetype of high-status men who use their status within programming communities as a tool to target women, I find the nature of these kinds of posts to be counterproductive. Therapeutic to the author?…
You're concerned that this is stacked against you, but the courts are stacked against the victims. So it doesn't really suffice to decry the one problem without addressing the other.
So perhaps you can see what it looks like to many women when you say, "Hey, I'm sorry this happened to you, but this bad thing happened to my brother, so _shrug_". Did your brother go to the courts and police to address these issues? It may been unlawful termination.
There is a large domain of behavior that is either nebulously legal or difficult to prosecute but which makes our communities much, much worse. It's counterproductive to tell the people victimized by that to stop talking about it. The solution is to go forward and find ways to set up our communities to protect people. And that can't mean just asking victims to accept that.