By all means, get your lawyer to confirm this fact for you, but: assuming you had the bare minimum competent legal assistance in setting up your company and its hiring documents, there is practically no such thing as wrongful termination in the US. In particular: if it is lawful for you to fire someone at all, it is probably no less lawful to fire them over a good-faith mistake.
Obviously, there are any number of things you can blunder into with your employment documents that can create a colorable claim for wrongful termination. But the reason everyone uses the same boilerplate legalese employment documents is precisely to avoid these kinds of claims, and to firmly establish at-will employment with no implied contracts of job security.
If you think you have an argument that firing this bizdev guy is legally tenuous, I have bad news for you: in your company, it is also legally tenuous to fire a developer who has only ever managed to push code that rm'd your prod environment.