This was an international flight and the Montreal Convention 1999 (and the European Regulation that implements it in all EU Member states) is applicable and air carriers are strictly liable for proven damages up to 100,000 special drawing rights (SDR).
'Strictly liable means that the airline accepts liability (no need to go to court and prove their liability).
So these guys think they can get more. Assuming the lawyers will get 30% that means they need to secure more than 130,000 SDR per passenger in order for the plaintiffs to improve on what the Convention gives them.
And 70% (100% less 30%) of 130,000 is? ... Less than 100,000!!!