Man the lifejackets...
You make good points, but you probably need to understand Annex 13 a little bit here with respect to OBRs.
It's not that the OBRs may not reveal information about data/information that's known. It's the fact that effort WAS made to recover the information which may substantiate other information that's already known.
You also need to look at what gaunty said:
It actually begs the question. Are we to base investigation results on basically uncorroborated evidence and "views"!
It wouldn't be the first time that "evidence" offered on recollection was not supported by other facts. The only way that can become incontrovertible is why CVRs are installed in the first place.
In other words, the OBR information really is invaluable to 'corroborate' other information, and also to validate other information that's gained during an investigation.
There are many 'landmark' investigations where OBR data really DID provide the 'key' to what happened MTL, and to disregard the effort to retrieve that data based solely on $$$-considerations, as was seemingly done with the PEL-AIR investigation reveals a very 'flawed' philosophy and understanding of basic investigation methodology by the investigation body conducting the investigation.
Remember too MTL, the purpose of the investigation is
NOT to apportion BLAME, but the way CASA approached things with the investigation under consideration might perhaps make you think otherwise.
But nothing I or any other PPRuNERs say/write is going to make the slightest bit of difference to TweedleDUMB and TweedleDUMBER I'm afraid, and unfortunately all we're doing is pissing into the wind.
Time to canvass the independents I think.