There is so much misinformation here. No surprise that pprune seems more and more avoided by real professional pilots.
I wonder who actually read the report the bureau d'enquêtes et d'analyses published about a month ago.
It is all in there: when did the copilot take a break in his flight training, what kind of psychological problems did he seem to have at the time, what happened when he applied for an FAA medical, etc.
Everyone who has the slightest understanding about the case will see that the lawsuit is ridiculous. Which doesn't mean is could not succeed, law sometimes creates weird outcomes.
And yes, as mentioned earlier, my understanding is that the lawsuit is not about "Schadenersatz" (=compensation about loss of income) but about "Schmerzensgeld" (=compensation for endured physical or in this case psychological pain). In Europe "Schmerzensgeld" is traditionally rather low, as such happenings are considered a risk of being alive, while in the US it can mean a financial jackpot.