[jarrett]

Legally, that's murky. There's still the oral agreement. Others have suggested that the oral agreement would be unenforceable due to the statute of frauds. But I don't think it actually applies here. So I think the oral agreement might, in principle, be enforceable. Being practically enforceable is another matter.

That being said, it appears the intention of the protocol is not to recommend a set of best practices for forming legal agreements, but rather to establish some community norms. I think the assumption is that anyone who violates the community norms will suffer a loss of reputation.

In that light, the analysis becomes easier. If step 3 happens and the investor subsequently goes quiet--failing to deliver a "yes" or "no"--then the investor has violated the community norms. (Even a "no" might be considered poor form following the oral deal, but it's certainly better than ambiguous silence.) Presumably, some community self-policing happens at this point, and if the investor remains obstinate, then word spreads and the investor is shut out of future deals.