"Inside the "Labo Phase", Lucci attacks Vegapunk but
Stussy uses her body to protect him. Sanji takes the bubble gun from Nami and traps Kaku inside a bubble ball.
Then Zoro attacks Lucci, both of them go through wall and flies outside the lab."
- Stussy is the one who truly saved Vegapunk
- Zoro just reacted after that and slammed Lucci against the wall(dehype of CoO but strength hype)
How is that different?
Stussy used her body to protect Vegapunk means that she is the one who truly saved him. Of course if Zoro didn't enganged on Lucci after that he would ended up killing both Stussy and Vegapunk.
Redon specifically said "then" Zoro attacks Lucci. Means that he only reacted after Lucci attacked Stussy that defended Vegapunk.