Never said that. Just said he didn't win fairly, for two reasons:
One: It completely contradicts the pecking order that Oda established beforehand which is Shanks < Primebeard < Xebec = Harald < Domi Xebec and HK Harald (HK Harald may be slightly stronger since he died 24 years after Xebec and the HK amp is probably bigger than the Domi amp) < Loki
Two: Shanks and Loki have no reason to he enemies. Shanks knows the truth of what happened at the castle and knows Loki is a good man, so if they fought it's probably not in the way some people envision it.