As far as the law is concerned, I don't see why a clearly defined contract should not hold in law depending on what the application of it is. But I'm not a lawyer so that's not something that I can even speculate about given how absurd some of the loopholes over there are.
I thought the whole idea of the smart contracts is that they don't care about the law, the justice system can not turn them over. Contracts based on math, Honey badger don't care sort of thing, it either executes on the blockchain or not. What's the point of troubling with it if some judge can invalidate it?
That was a great idea... until Vitalik destroyed it by forking ethereum to invalidate the DAO contract and its results.