I would classify this as "unintended oversight of recent new feature", and fixing a problem with a feature is a bug. The goal of the feature is convenience, which it's great at, but this one particular case forces Dwarftown traversal to become a big hassle if you always have to watch out to make sure the ratling isn't in the way. As a bonus, it seems like the logic already exists for certain NPCs in Terinyo.
As the ratling is demented and likely significantly tainted by chaos, I see no reason why character's strength would deter him from doing something crazy.
(on a related note, I used white necromancy for the first time and my homunculus almost bled him to death, but he's peaceful again. hopefully quest still works!)