When an object is stolen from a cache which was otherwise destroyed, 1) that is by definition a statistical anomaly, and 2) it may contain information from a time/place that is otherwise irrecoverable, which could make it valuable.
Between these two facts, I think it would be way weirder if everyone quietly ignored the historical record of a specific artifact just because it was stolen. Imagine walking through a museum with a tour guide who is able to give mounds of information about every piece on display, until you ask them about a certain bust, and they say "oh we don't talk about the history of that piece" and you say "why not?" and he says "because it's not relevant".
Be honest, what you're actually saying is, "this information isn't relevant TO ME."
I feel like there's some misunderstanding here. I am not at all advocating that the fact that objects had been stolen be suppressed. I'm advocating for the explicit opposite. What I am, however, saying, is that I find it odd that museums are allowed to keep these stolen artefacts, while the woman in the OP was not.
Can I recommend a podcast called 'Stuff the British Stole' by Marc Fenell (aka 'That Movie ... Guy'). It looks at exactly this, including situations where an artefact only exists _because_ it was stolen.
Person1: A
You: This sounds like B, which is fallacious.
Person2: A
You: Again...this sounds like B, which is fallacious.
Me: No one is claiming B
You: I never said anyone claimed B. I said this sounds like B.
Sound about right?