Well, obviously I didn’t know much about that case, so I’ll take the correction. My thought was that coffee is supposed to be hot and that the vendor isn’t responsible for the customer’s behavior; but there does seem to be more to it than that, so I withdraw the suggestion.
As for the other two, I remember reading about the first one in TV Guide’s news column at the time, well before we had the internet, so probably around 1980. I don’t remember any particulars of the other one.
I doubt that they actually do represent an extreme, though, since anybody can sue anybody for anything.