I hope the NTSB does individual interviews with each crewmember and then ask them as a group with everyone in the same room. I'm sure the replies will differ a lot....
Differences include new info from a different view of the accident
If critical differences occur all you need to do is to re-interview to re-enforce the investigators understanding. It may not be productive to mix interviews in the same room as you may subdue comments that have subjectivity in them.
In the end nothing is that factual unless it is also supportable by other means.