I would expect people to realize that bitcoin has the potential to crash to zero and make that stipulation in a contract that the transaction is based on current value and they won't be compensated with any other currencies.
I just posed the scenario of someone filing lawsuits to be compensated. I mean people sue over spilling hot coffee. I can honestly see this happening at some point (provided bitcoin crashed, that is).
People do realise this - but I reiterate that no one would be stupid enough to accept a contract where they would have to compensate someone if Bitcoin fell. From a logical standpoint, it means you'd have a hedged bet whereby if Bitcoin goes up you profited nicely and if it fell you were compensated. Either way you win - which is great for you as the seller, but shitty for the buyer.
As to lawsuits - there are people who always feel they a served an injustice when something goes wrong. It doesn't mean they are right or justified in suing - nor does it mean they will win.