If they actually had a case against Facebook and Facebook had caused actual harm the amount would be much higher.
Any company that has successfully filed an employment green card (especially at that scale) is favoring immigrants over citizens by definition. The EB green card rules are highly outdated and a reform is long overdue.
They argued that a company should not be able to do that if they can hire a minimally qualified US candidate, AKA someone who checks the job requirements.