Vaguely Legal Answer
From what I could glean, there were Lebanese passengers on board who died and/or were injured, whose tickets gave them rights of legal action in Lebanon. An old treaty called the Warsaw Convention 1929 (check the small print on your ticket the next time you get bored) probably applied.
Their next of kin chose to pursue those rights in their home State. The families spooled up the Courts in Lebanon, (mostly following the Civil Law tradition, but with a generous dash of local representative Beirut flavour) who then did their Criminal thing, and followed through with the compensation ruling.
The insurers for the airline seemingly came up with the none too smart offer of US$25,000 per family for full and final compensation some time ago. Hey presto, several years later they have a much larger compensation bill.
The interesting thing about this, is that it will have a positive impact on the Lebanese families affected by ET409, as this is the first time a Lebanese Court has ruled publicly on an aviation case for criminal and/or compensation purposes.
Probably the right time to sell your shares in aviation insurance companies.