You know, this is sort of a form of “Whataboutism” in an alternate way. Example:
People should not exceed the speed limit.
What about emergency vehicles?
Okay, fine, except for emergency vehicles.
What about someone rushing a woman in labor to the hospital?
Okay, fine, and except for women in labor.
What about if you have to save Earth from Nazi aliens?
Okay, what? No.
Some people can go on and on. Most people get the gist and move on.
So not so much a fallacy but an annoying human behavior. Not all things need to be explicitly spelled out in axiomatic detail.