Page One didn't use adv CoC on his neck against Big mom...
Ragnarok touched Luffy because he was crushed against the floor by the attack and couldn't go anywhere.
Law did react, but he's seen that shit before so no words were necessary to show confusion.
"How is it possible that Zoro can do X...- oh wait I've seen Luffy and Doffy do that, it is shocking a subordinate has it but I don't though"
You are ignoring the main point of narrative around Kaido's words so any argument I give will be even easier to ignore, if you ignore the manga. Nice hypocrisy there to claim I am ducking, while ignoring the primary point of my argument.