I would be much more comfortable if I could see all of the emails with each side clearly stating their case, and then the developer's calm and rational ultimatum to go to the public.That's the problem with whistle-blowing. Usually, there's a period of negotiation that occurs before it gets to that point. The situation has been developing for weeks or months and nothing else has worked. Suing is too expensive, so the wronged takes the matter to the public.
It can be damaging to the whistle-blower's reputation because, from the perspective of almost all of "the public", it's the first time they're hearing this news. They don't see the months of failed (or even bad-faith) negotiation. It seems like a drastic, hair-trigger decision to expose the matter, because it's the first time they are hearing about it. And people like to kill the messenger and don't like to hear bad news about reputable companies.
If the case and ultimatum were clearly communicated, Miso would have been prepared for the negative PR by releasing their version of events.
Sounds like a Ned Stark blunder. Experience has taught me that threatening to do something like this is a bad idea-- it gives your adversary time to prepare for it. Don't threaten; just do. If you're in this sort of fight, you want them to be surprised and capitulate in 12 hours. Saying, "this is exactly what I plan to release about you" is a bad idea for several reasons. First, your adversary has time to prepare. Second, it can become illegal (extortion in some cases, although most likely not in this one since there was a pre-existing contractual agreement).