Hawkins was not KO, he tried getting up unlike white eyed Zoro.
Official translation
Am very confused as to what point yoyou are trying to make.
Hawkins stayed on the ground. He never tried to get up whilst Kizaru was there. Just read chapter 510.
As for Zoro. Even in the panel you posted, Zoro is still awake, he even says damn it. That is not a knockout. Even in the panel where Kizaru is next to Zoro and says it is already too late, you can see an empty speech bubblenext to Zoro.
Also if you continue reading, you will see that Zoro was trying to get up but his body didnt listen to him. Chapter 511.
Even in the official translation Kizaru says the reason Zoro went down after 1 hit was cause he was tired. We know Zoro was not fine the entire arc, he had notbern fina since thriller back. So even Kizaru knew that Zoro would not have gone down with only 1 attack if he was not tired. Mind you, out of everyone that kizaru defeated, majority of whom went down after 1 attack, it is only for Zoro that he commened he was tired which is why he went down after 1 attack.