Hello Martinidoc, I do not have the requisite experience to determine whether you are a lawyer with medical qualifications, a doctor with legal training, or, frighteningly, all of the above.
I understand that a very experienced law firm has taken this case, surely they must be aware of the facts as outlined in your post and the probability that such an action would ultimately fail. Do they see the possibility of an out of court settlement as a final and profitable outcome? And without wishing to invoke the specter of ethics and its highly mobile goalposts, is it conceivable, as has been known to happen this side of the Atlantic, they take the case merely in order to provide work for themselves?
The extent to which the airline industry will suffer collateral damage is as yet unknown, but as there are quite large sums of money involved here one thing at least is certain, the lawyers will profit handsomely.