125.227(f)
In the event of an accident or occurrence requiring immediate notification of the National Transportation Safety Board under 49 CFR part 830 of its regulations, which results in the termination of the flight, the certificate holder shall keep the recorded information for at least 60 days or, if requested by the Administrator or the Board, for a longer period. Information obtained from the record is used to assist in determining the cause of accidents or occurrences in connection with investigations under 49 CFR part 830. The Administrator does not use the record in any civil penalty or certificate action.
I appreciate that this is from the american rule book, I am assuming that the french/canadian FAR's are similarly written. So, my interpretation, is that there is nothing here that would actually prevent the information being passed to another authority/legal hearing, however, the Pilot's are protected from litigation from the FAA, I.E. ATC may be able to use the information to prove beyond reasonable doubt that they are to blame, and at the same time, the pilot's are protected from and litigation following this incident.