Two diffferent agendas...
Crash investigators are there to uncover the truth of what happened without regard to finding fault per se and their goal is to advance safety.
Lawyers are there to win cases any way that they can (in the States we use an "adversary system" in court, with the two sides fighting it out in front of the judge and the jury) when the truth of what happened may well go ignored or perverted. The only advance to safety is the very dodgy premise that a multi-million dollar judgment against a manufacturer "sends a message" that they have to work harder to develop a crash-proof airframe.
For instance, there was a Beech Bonanza accident involving pilot error, according to the NTSB. It looked for all the world as if the pilot had simply gone below the MDA on an approach and done a CFIT on very short final.
The lawyer for the dead pilot's family managed to convince a jury that there was something wrong with the aircraft that caused the crash.
The neat thing was that, post-crash, there wasn't any way to say whether that was so by looking at the burnt wreckage. Of course there was a remote possibility that the aircraft was on fire on final for no obvious reason, just one that went disregarded by the NTSB! If you can manage to get your case in front of a jury of twelve ignoramuses then all bets are off. Here it seems to have started before we even get to court at all.