Ok by Shishio's logic:
- Doffy didn't kill Rosinante because Rosinante was still able to using his DF and protect Law, instead of immediately dying
- Akainu didn't kill Ace because he didn't instantly die and had time for last chat with Luffy
- Zoro never KOed Kaku because Kaku was still conscious and still hearing "You're fired" message
And the list goes on.
-Doffy did kill Rosinate because one can still live for some time after taking a life threatening attack until their body reaches the limit. People with kill shot stabs can also live for a few minutes before they die
-Same for Ace
-Kaku was K.Oed almost instantly though, pretty much same way killer was.
Zoro took the stab, squeezed the scythe, ended the fight and then we got a hunger panel from Zoro same as Luffy. So tell me how is it Killer that made Zoro pass out?
What did that stab do that made Zoro pass out? Was it pain? Because Zoro some how lacks pain tolerance? Yet he was squeezing the scythe and smiling and no indication of pain was given?
Was it due to blood loss like Zoro pass out from the blood due to stab wound given to him by buggy or how Luffy nearly died due to blood loss? Was there indication of that in manga?
Or you know simple, eating poisonous food for days, then starving and then having that stab as a catalyst made Zoro pass out. Why did Oda draw hunger bubble on Zoro instead of expression of pain?