Lubitz didn't come straight out of flight school to crash, he was flying the line with Germanwings for about 18 months before the crash. This time factor in itself would distance the flight school's implied responsibility for psychological snafus, if ever noticed & addressed, during his training. Ultimate medical fitness for flight rests with the German licensing authorities and the employer. Suggesting that this flight school was responsible for the crash 18 months after graduation, is like blaming a bartender for last week's hangover.
What's bizarre is the assumption by plaintiffs that a U.S. court would somehow embrace jurisdiction of this deliberate crash in a foreign country, by a foreign crew, operating a foreign manufactured & registered jet, by a foreign airline.