9/11 is a lie! The survivors and the relatives of the victims are amongst the most vocal critics of the official version of events and support a new investigation.
Any they are experts...why, exactly? Cause they were there? If that's the case, I gotta find some better employment, cause I am pretty sure by those standards I can run the Fermilab particle accelerator; I went on a tour there once.
One would presume that those who lost family members are 'experts' on the details the 'official version' of 9/11 and how the report was generated because they would have tended to have paid more attention to these details than the average Joe.
But almost all of them took quite a generous settlement from the US Government on the condition that they forget it and move on as I recall.