it's not that zoro didn't dodge in time, he had to momentarily stop the attack for the others as a part of the the plan.
1- zoro tanks the attack
2- luffy attacks kaido
3- law traps Zeus / killer and zoro immobilize Napoleon and Prometheus
4- kid and law kick big mom out of onigashima.
No,, that is just trying to make excuse of the things. There should be no connection between Haki and DF abilities, they are not sea stones. Its just BS to me. I would rather he just say BM is too big for his room.