Don:
You are absolutely correct. You brought up a good point, and sorry to say it reinforces mine. To teach the inspectors about GFCIs.
A case in point, dont know why I didnt think of it earlier, When my daughter bought a home they had it inspected, old wiring two-wire romex, and the inspector used a typical GFCI testor in the bathroom and he said the gfci had to be replaced because it was defective. The previous owners had just had it installed. No the inspector did not use the test button but relied on his testor to make this determination.
The wiggy test would have worked too.

Mark