Reading the GP comment (going skunk), I wondered if the factors behind that turning out positively was the position of the fixer relative to the code/systems in question. If they're not stepping on anyone else's toes it works great.

This comment echoes that sentiment a bit, I think; there's an implicit dependency in there on the project not having a collective structural investment, whether that's explicit (overt, with explicitly delineated boundaries) or implicit (implied, fuzzy, part of collective culture), on the thing being fixed.