Will this potential employee throw a fit when we don't use the libraries he wants? Probably not (like I would assume of most professionals), but this new found infamy would make me as a recruiting company think twice.
I think the situation could and should have been resolved in private. I know there are more clarifying emails, but we don't get to see them. If I were considering hiring this guy, 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. Even then, I would (as a potential employer) be even more comforted if the post itself had a calm and rational voice. (I believe the voice is mixed at best.)
I base my claim that this could have been resolved in private on the fact that Miso resolved everything so quickly. If the case and ultimatum were clearly communicated, Miso would have been prepared for the negative PR by releasing their version of events. Instead, the company payed up not even 12 hours after the story is published. This leads me to believe that communication was poor between the parties.