Scum is anything that isn't village.
However, and we've discussed this, the most important thing for village to figure out about a 3P is if they have an inclusive or exclusive wincon (they win with another faction, or they can win making all other factions lose), and if they have an inclusive one, does it include village.
As far as players and meta goes, I tend to want 3P dead more than just about anyone, but even I will set aside a 3P if I can be reasonably certain they are "true neutral" can win with either side or their inclusive wincon includes village. The trick is convincing me of that.
If I think a misyeet of a villager is happening I will vote any 3P in a heartbeat if no other ways of voting out a scum lean are available.
So far feel good about Dubz' claim but I haven't poured over the list.