yotsuya said:
And the words of Padme may be ringing in his ears, “there is still good in him.” Kenobi tells Luke that he once thought that as well, and this may be that moment. Even though Vader has just said he killed Anakin, Kenobi may not be ready to accept that yet. There are lots of ways to read this that make sense in light of everything else we have in the main Saga films. We don’t have to assume that Kenobi missed the perfect chance to kill him. Killing a being who is just one of many evils in the galaxy won’t change the evil of the emperor. And we don’t know what images of the future Kenobi might have seen that leaving Vader alive is the best option.You know, this would be great, fantastic stuff if the series bothered to show us any of that. If we got to see Kenobi try to bring Anakin back only to fail. This never actually happened, though. He beat him, said his friend was truly dead, and walked away. Hell, even Obi-Wan hearing the voice of Padme saying that would have indicated it enough but not even that is expressed. And considering this series is made for casual SW fans as well as diehards, something like that would have been warranted if they were trying to get that idea across.
There’s never an any actual moment that lines up with Vader saying Obi-Wan thought there was good in him. It wasn’t shown in RotS and it wasn’t shown here, despite you filling in the blanks for the writers who should have known better. If they had written it in a way that reflected what you wrote, it would have made more sense. But they didn’t, so unfortunately, all of this? Is you writing the script for them.
So what we’re left with is an Obi-Wan who seemed to have every intention to kill Vader, to the point of even landing a blow to his face, internalizing and vocally emphasizing that his friend is gone forever, DEAD, and then deciding to let him live anyway with zero indications of any potential thought to there being good in him still. Not even an attempt to convince him. The writing and directing do not reflect it, so there is zero reason to believe it.
JEDIT: And even then, I still think the confrontation should have ended with Vader escaping rather than Obi-Wan sparing him. It would have absolved Obi-Wan of the responsibility, even if he didn’t intend to kill him. Really, this whole show dropped the ball on that idea in general, tbh.
There are other options and no, this series does not need to explicity address exactly what happened. There are plenty of other instances in the saga where things are not explained in detail and we are left to guess.
What we saw may have been the extent of what Kenobi could muster and he had driven Vader back to a point where he can leave and going back to protect Luke is more important than finishing Vader. So a combination of other priorities and Vader being (at least momentarily) defeated in battle are the most likely reason why Kenobi left him alive.
Expecting Star Wars to spell out every little reason for everything totally ignores how the movies handle things. Most of us don’t question the OT because we first saw it when we were very young. But there is a lot it never explains. Lucas wasn’t a good explainer. What he put in the PT was certainly very subtle hints to things and tie to the core of the story.
So no, nothing I suggested is explicitly mentioned and nor would I expect it to be. I didn’t question that scene at all. What is there to really question. Kenobi faces the being who once was his friend and fights him to a point where he can walk away. Is it any surprise that he walks away? He has been going on the entire time about protecting Luke and Leia. That is his duty. Why would he risk that Vader might rally his strength (like he just did) and defeat him and leave the twins unprotected. Vader is not the only danger Kenobi has to think of. Just because we are not told the inner working of his mind does not mean there is any logical failing of the story. If that were the case there are plenty of larger questions that they fail to answer in the movies. Fans have spent years trying to answer those and some have made it into canon. We went into this knowing that Vader would not die and why Kenobi leaves after that victorious round of combat serves the saga regardless of the reason. So do we really need the reason spelled out in detail in a very un Star Wars fashion?