End of the day, all considered, what it comes down to, I suppose, is how one weighs the importance of one fact or factor against or over another, and ultimately that is a subjective matter. My own interpretive bias, needless to say, leans in the direction of placing greater emphasis upon the collected and collective biographical and psychological facts of Ringo's life than the details you've listed.
Why that specific bias? Because my own personal experience, life experience, has impressed upon me that many if not most otherwise apparently unanswerable questions with respect to human behavior can be answered, or at least explained in large part, by investigating a person's past, that private, more intimate history which typically provides the necessary context for getting at some approximation of the truth.
That said, those details cannot and should not be ignored, they need to be considered and accounted for to the extent that that is possible, and when taken in sum they must give one reasonable pause, but in my opinion, while they are of pertinent interest, the deciding issues for me remain the ones I've stated. (You mention law enforcement officers. Are you including in that group forensic profilers and psychologists?)
Anyway, what has any of this to do with why Wyatt Earp concocted his incredulous story? I have my own speculation about that, but that's all that it is.