The tribe had a law, Gabrielle must be executed. Accident or not, she was to be executed. Of course, that's silly. We all know it is. Her death would have served no purpose in the "greater good" of the Xenaverse. Xena was justified in saving her friend from a silly execution.
Flashforward to the end of the series and now we have "A Friend in Need," an episode that is all about "The Greater Good" and self-sacrifice.
Xena's actions in Haguchi, some 35 years earlier, were done in a drunkened state and she is definitely guilty of the loss of innocent lives. I'm not talking about the poor blokes that beat her up (who were retreating when she set the village on fire) who may have died. I'm talking about the thousands of people who died needlessly, who huddled in their homes. Sounds like the burning of Cirah, Callisto's village, to me.
WHAT?? Xena's just supposed to stand by and let these people suffer (definitely unlike her) because it's against the "Greater Good"?
Were we watching the same series?
I tend to think not, because Xena finally figured out selfless actions. Giving up the chance to stay with Gabrielle so thousands of people may know peace, is not only selfless, it's also part of the "Greater Good" how it applies it the Xenaverse.
She did say to Gabrielle:
Don't you know how much I want to let you do this? But if there's a reason for our travels together, it's because I had to learn from you, enough to know, the final, the good, the right thing to do. I can't come back. I can't.
Gabrielle accepted it, because she knows that what Xena said is true. As much as she wants to open up that urn and pour those ashes in, she knows that if she does her life with Xena will change, forever. And it would be completely against her nature: serving the Greater Good.