Oden vs the boar could be like Zoro vs Kaido scar, using it without knowledge/mastery.
Both of them are not Advanced Conquerors displays.
Oda made it pretty clear on
ALL instances that Ad CoC was used with
heavy black lightning and not only that but the users wouldn't touch another.
With Big Mom, Luffy, Roger and Whiteboard it was all the same and we
know those attacks were indeed covered with Ad CoC.
Now people tend to
speculate that Zoro used in Asura but absolute nothing in the story suggests that, in fact Kaido's dialogue implies he wasn't since he proceeds to say that only a
handful of the strongest are able to do it.
What probably happened on Zoro's and Oden's boar attack was that they were probably leaking CoC while attacking just like Luffy have been doing in the fights against Doffy and Katakuri.