Actually we have the Warsaw and Montreal Conventions. However, much to the chagrin of the legal community 'mental stress' or 'anguish' has never been considered to be a valid legal claim. The Heathrow incident doesn't qualify as an accident (under either treaty) either.
So we see the lawyers going after the manufacturers, the airports, the engine makers instead.
I've had a couple of diversions, and a couple of shut down engines in my flying days. 'You can cut the silence with a knife' type of incidents, but no flames that I saw.
But if somebody came to me and said 'sign here, and I'll do all the work' costs me nothing and might mean some cash in my pockets. I think I'd still decline, hating the bottom feeding scum lawyers, but a bit of revenge for the crap (lack of) service is always appealing.