I find it even more strange as it is at the end of the chapter, maybe oda wanted a dramatic finish for the chapter ?
Oda just wanted us to say "oh no, harry up chopper"
Which means next chapter will be Chopper focused!
But I feel Oda could have handled this better!
For example, Hyo and Drake vs Apoo, right!?
Hyo asks his partner Drake saying: hey kid, I am not sure when will this medicine will take full effect, but when it happens... I trust you will take care of me before I hurt anyone" implying he kills him!
Not only it serves same purpose!
But also, shows that Hyo didn't yet lose hope, Also give dramatic scenes for Drake as Marine soldier to having to kill an innocent old man... it just makes greater drama and saves character face and words they spoke before