While I agree this is a good learning experience, and so deserves some attention, we disagree on the lesson. The actual lesson, for the founder, is this:
>>Verbal contracts are binding.<<
You cannot legally agree to something on the phone and then change your mind when it comes time to sign the written form of the contract. Period.
We don't even really know that this is what happened. Even if it were, we don't know the context or the tone of the e-mails leading up to this. You are jumping to a ton of conclusions from a post whose goal is just to induce a lynch mob... even the specific quotations, were they actually 100% accurate, are not things I can easily see having been totally reasonable if (and I personally find this much more likely) the contractor was being belligerent and was doing little more than threatening lawsuits and ownership claims in their side of the correspondence (possibly even /before/ there was the alleged billing dispute).
I would think the written contract becomes a new agreement that supersedes the verbal one. What if there's a dispute in the terms of the written contract that was never brought up verbally?
I actually am looking for clarification b/c I would be interested in knowing if the prior verbal agreement trumps all future written discussions. It just isn't what I guess would be the case, and I can certainly see how someone would interpret being asked to sign a contract a renegotiation of terms, which is what I think happened in this case.
Doesn't matter. The founder hired the designer verbally. I imagine that the judge will first determine if there was a verbal agreement, and then, if there is disagreement about the terms, use common sense and vague standards to determine the correct remuneration. It's not actually that complicated.