The case where a Peanut allergy sufferer sued the airline and the airline sued the peanut eater and there was a counter suit from the peanut eater would be interesting .
I would really like to see a Charter case in Canada of course against Air Canada ( or WestJet I suppose) by a Canadian flying between two points in Canada being on a no-fly list. Especially if they were on a list started by America because ( as happens) the flights happen to get close to American soil. Or in terms of this thread, for being disruptive by eating peanuts.
I suspect that the Supremes might find for the passenger and then be overridden in practice for "national security " reasons. But who knows... they might use the overall get out of "just and reasonable".
FWIW mrs tpl is intolerant of Oysters. raw or cooked. But not allergic, she just pukes.