This feels very natural though, in a "principle of least surprise" kinda way. This is what you'd expect a properly designed switch statement to do.

If I aimed and shot a gun at my foot and a bullet didn’t go through it, I would trash the gun.

I agree it's not the best choice. I mean it's true that you almost always want fall-through when the body is empty and break where it isn't but maybe it would be better to at least require explicit break (or fall-through keyword) and just make it a compiler error if one is missing and the body is not empty. That would be the least surprising design imo.