For me, the interesting thing about this ep is that up until then, when the story of the shooting at the OK corral was portrayed, the Earps and Holliday were the good guys, and Clanton and company were the "bad guys". ("My Darling Clementine", etc). This was the first time that the Earps were marked as the "bad guys". Interestingly, the last 2 portrayals - "Tombstone" and "wyatt Earp" - the Earps are again the "good guys".
Ever see Hour of the Gun (1967)? James Garner-as-Wyatt was one ruthless SOB, so the revisionism had already started by the time Spectre of the Gun aired.
IIRC, Costner in Wyatt Earp wasn't exactly the typical "good guy", either.
I'll have to check that movie out, I never saw it. And while mostly true about Costner's portrayal, I felt the Earps were still the "heros" of that account.
Another interesting aspect of the incident that I only became aware of recently was that there was a political component to the fued. The Clantons, Mclaureys and Sherriff Beehan were apparently Democrats - pro slavery and somewhat anti business. The Earps, and the town marshall were Republicans -anti slavery and different business and ownership theories, and this apparently was a large part of the animosity between the groups.