Anytime the metal pin in the center of the switch is allowed to extend, the BU light circuit will have continuity; when the correct roostercomb is in place the pin will only extend when the "divot" in the plastic shoe is in line, in all other gears the plastic shoe keeps the pin pushed in (see pic below).

The test results you posted are typical for the wrong 2-eared roostercomb or a correct one with the end of the shoe broken off.