shebbesonian,
Would ?? ??? ???? ???????? apply here?
The issue here is not whether the person is telling the truth. The issue is that the person may rely on kulos upon which other people wouldn’t rely.
If you applied ?? ??? ???? ???????? here, you could probably use the same rationale to eat food with any kosher certification as long as there is a Mashgiach that is shomer shabbos.