He did kill one guy by turning him into leaves, to be fair (Episode 49: The Four Seasons of Death). But other than that, all the times you see him slashing at organics you can assume them to be disabling/crippling blows, not killing. Even if it seems unlikely they'd survive that or if there's an explosion short after that should have done them in, Jack didn't kill them. That's what word of god states (and has always stated, this isn't a retcon).
A Retcon is "Retroactive continuity" if the word of god is supplying information that supplies information or changes information to the past... that is what it is
Unless I guess it is a clarification on something that was very unclear.
Which frankly... Person gets slashed, falls down, isn't moving, isn't breathing, never shows up again, and Samurai Jack SPECIFICALLY spares someone else... Is kind of... not unclear. It is just this weird assumption of "Well you didn't actually SEE their internal organs on the outside, that means they are alive".
I mean it is a LOT more clear then Jet's kind of... honestly official death (mostly because... He was dying and how the heck could he have survived that?)
and forced them to defend by aiming a neckshot.
I dunno he seemed pretty surprised he blocked that.
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OHH MY GAWD!!!
Samurai Jack is the Akuma of the freeken cartoon universe!