My limited understanding of this issue is that they are not trying to overturn the Montreal convention, but rather saying that the 1500$ limit does not apply because Article 22, para 5 of the article states that "The foregoing provisions of paragraphs 1 and 2 of this Article shall not apply if it is proved that the damage resulted from an act or omission of the carrier, its servants or agents, done with intent to cause damage or recklessly and with knowledge that damage would probably result; provided that, in the case of such act or omission of a servant or agent, it is also proved that such servant or agent was acting within the scope of its employment." [underlining mine]

They are trying to use an alternate provision of the convention, not reject the convention. Whether they will succeed or not is another matter.