notapilot15.
"External parties wouldn't see all the data. Why would EK/DCAA/GCAA show rosters to NTSB."
Sure they would
ICAO Annex 13!
The State of Registry, the State of the Operator, the State of Design and the State of Manufacture shall each be
entitled to appoint an accredited representative to participate in the investigation.
Rights:
Participation in the investigation shall confer entitlement to participate in all aspects of the investigation, under the
control of the investigator-in-change, in particular to:
a) visit the scene of the accident;
b) examine the wreckage;
c) obtain witness information and suggest areas of questioning;
d) have full access to all relevant evidence as soon as possible;
e) receive copies of all pertinent documents;
f) participate in read-outs of recorded media;