Would be interesting to know which carrier this was?
It was one of the US majors but I've forgotten which one so although I have a suspicion it would be unfair to name the wrong one.
WHBM : The question is, do those conditions override the law? Also, it might be permissible on one jurisdiction but not in another. This is similar (I accept not identical) to the Ryan Air €60 boarding pass debate. People agreed to the conditions and as unreasonable as they may be, they have been enforced. Apparently there was a court ruling in Spain but they seem to have ignored it and are still making the charge as the recent incident proves.
I have a friend who's a laywer and has been involved in the aviation business. I don't feel it's fair to phone him specifically to ask his view on this (he might charge me £300 an hour!), but I will bring it up in conversation next time I see him.