I wonder what kind of "evil" players would save him ... twice. O_o
They'd have to change it a bit, so that is not necessary to free him from the windmill. A narrative explanation could be that the goblins got bored at one point, and he manages to escape.
I haven't sided with Nere yet, so I don't know what's happening then. But I think it would make sense if he didn't kill all gnomes, as they might still be of use for him. I severely doubt he is the kind of guy who likes to get his hands dirty and does all the chores by himself 😄
But yes, a lot of changes would be necessary for this to work.