I vehemently disagree that just writing code makes your responsible for it's use. We are so bad at writing good code that all programmers would be living on the streets or in jail. And that is not malice, just how little we understand or underestimate complexity. Which becomes apparent if you indeed try to create some formal proof and give up after 30 pages.
I also believe your last statement does not recognize the vast issue there is with the smart contract world: I am more of the school of Erlang/OTP: just let it crash these days. If you cannot correct a state, we cannot write software for it. No matter the proofs and auditing. If we cannot correct an erroneous state, we are not capable of writing software in that system. And that is smart contracts. Not space craft where we often can upload a patch and steer the other way, not cars where we detect a deviation and correct it. Smart contracts are: if it's done it is irreversible and there are no programmers, provers or auditors who can predict or prevent that. Rollback must exist or this all will go to shit. Which is what will happen.
Edit: I actually do not believe cryptocurrencies have a chance unless there is rollback (something like refunds without merchant consent). I just cannot see what rollback means in this context: I read papers with scifi type of stories how this would work but it does not mesh with cryptocurrency obviously otherwise.
