The europeans just take advantage of the low costs in the US compared to europe, same as a lot of their other companies do as well.
And the weather - it's why the major flight schools are in sunny AZ or FL, same as the baseball pre-season camps.
Realistically, THIS flight school has been sued in THIS case because it is a wholly-owned subsidiary of Lufthansa, as is GW. Ultimately, it is all the same big bag of money.
And it happens to be in a more - generous - jurisdiction. (Maybe - it's of note that none of the U.S. flight schools that trained 9/11 terrorists was ever sued, although at least one failed, later, due to shunning by banks and customers.)
No flight school, in general, is responsible for anything other than making sure the applicant meets the minimum requirements (money and a Class 3 medical). It's not
their job to do the FAA's (or LBA's or FBI's) job. Sorry, chuks, those are
our rules.
But - this was a branch of DLH, and therein lies the difference. If DLH had been smart, and contracted with a U.S.-owned school, or simply told Lubitz "go find some Joe CFI with a Seminole in the U.S. - we'll pay for it." - no lawsuit. It would be tossed out after a 15-minute hearing, and the lawyers would know it was a money-losing proposition, and not bothered.
Instead, DLH tried to be "cute" and run their own school (because it saved them even more money) - and it has returned to bite them.