Having translated the "Mission" statement of that report (which can be found here) :
http://aerofuites.com/exp-jud-juin-2...nique-du-2.pdf
It becomes clear that they were working at least in part *with* the BEA and reviewing the conclusions, not in isolation - so the idea that the BEA may be withholding anything doesn't stand up to scrutiny.
I'll try to translate the whole thing, but it'll take some time.