There's no slippery slope it's just an entirely wrong way of looking at ethics not only in this case but in general. Usually when people have these severe and obvious shortcomings it's because they're lying to themselves in much the same fashion that Dostoevsky masterfully illustrates in his writings.

The closest physical analog to this hack would be that someone picks the lock on your house and ransacks it. I'm sure you'd agree that it is not morally justified just because your lock sucks or because the thief had skill.

@bitcoinplebdev 100% bears the responsibility of protecting himself from predators which he failed to do and took accountability for it.

The hacker is still a piece of shit for this. There was a responsible way to demonstrate the hack, report it and receive fair (possibly even the same!) compensation as what he took. It's malice pure and simple. There's a very small pool of people that could have done it and I suspect this isn't over.