executive runner - you are correct. Being let go without cause without any explanation or substantiation of the action is incredibly ill advised from a litigation perspective. In fact, it is insane. Don't they have a general counsel? Access to legal advice? Any organization worth their salt would have a for cause dismissal prepared in writing (already reviewed by counsel) to present to the executive, and would at the same present that document at formal meeting in an office with calm, prepared witnesses (typically HR) and a senior member of the Board. Emphasis would be put on being factual, detailed, and professional. The fact that this appears not to have happened speaks volumes to be about the USATF. Of course, one likely explanation is that they did none of this because they didn't have any plausible grounds to terminate Logan, and just decided to wing it. Indeed, it is correct to question what kind of qualified executive would step into this mess. It also raises questions to sponsors as to what the heck they are paying for.
And while a "for cause" firing is dependent upon the language in the contract, you are also correct that it is often the case that an organization cannot sustain the burden of proof unless something illegal has been done or another act which stains the organization's reputation significantly.
Forget about whether Logan was the right man for the job. If indeed he was terminated in this way, well, USATF is one broken organization. Ironically, of course, no one at the USATF can speak to the process used, because of course they will cite the risk of litigation.