I can think of a couple of concrete examples in which the tubing decal would be mostly correct, but someone examining the bike would think otherwise.

Sometime in the early 1970s, after receiving customer complaints about oscillation, Nishiki switched to plain gauge CrMo on the seat tubes of its 25" Competition frames, the main top tubes and downtubes of which remained double-butted Ishiwata CrMo. They continued to use the same "guarantee double butted CrMo" decal after the change, despite the obvious need for a smaller-diameter seat post. Someone looking just at seat post diameter would conclude that these were plain gauge frames.