I think people can still find it off-putting that after all the evidence they provided you to get to that point, you're challenging them to prove they aren't complete frauds. Like you could has spent 30 seconds googling them and verify they are legit, but it seems you didn't even bother to read their resume. Not saying it's the case, but rather that not everyone is aware of how good the frauds can be at presenting themselves and bullshitting through interviews.