That may be due to a quirk of how we use it in English (and maybe other languages, but I can't speak to that). For some reason, unsafe or not safe isn't always perceived as a logical negation as some other concepts usually are, and is instead parsed as opposite of safe. "Verified" seems to suffer from this less, but is also less strong in what it positively implies.

Is it possible that the link to personal safety of the terminology is what provides the best positive connotation in terminology but also causes this unwanted ambiguity in negated interpretation? If so, that's an annoying catch-22...