Well yeah. The direct interpretation is that, if someone teaches an art called Gwonbeop, then he learned an art called Gwonbeop to teach what he had learned.
Oyama didn't teach kwonbop. He taught Karate. Or is he another party to your Grand Conspiracy?
Let's look at the books he wrote. Nope, no mention of kwonbop in any of them. What did he call his art? Nope, no mention of kwonbop there, either.
So what, in your fevered little mind, would lead to him lying about his training?