In Stative verbs^x, Clauses^x, Articles^x

The woman is a TV reporter who is standing in the hotel elevator. There's nothing wrong with this sentence. "Detective: I'm looking for two suspects: one is a man; the other, a woman. Here are their photos. Have you seen them? Helpful Janitor: Sure. The man is an executive who is...

Neither of your natural-sounding examples has an indefinite article followed by a time unit followed by "before" within an "if" clause. It seems to me that one or more of these factors must be contributing to the difference we sense. "I think we have met before" has no article and time unit,...