RING magazine ratings aren't any sort of holy scripture or high authority. Sometimes the guys favoured are mystifying choices. Sometimes they are pretty good indicators but we should never take it at face value. Compare Henry Cooper's record against top-flight and second-tier opposition to Brian london's and you'll see there's not that much difference. Cooper has a few good wins, the best being that decision over top-ranked Folley, but he also dropped decisions to Roger Rischer and Amos Johnson - second-tier or journeymen heavyweights. Patterson and Johannson sparked him cleanly and early, as did Folley in the rematch.
You're calling into a question a decision reeks of corruption. Maple Leaf Gardens went nuts that night because they knew that, finally, the hometown guy was champ. Chuvalo didn't have a scratch on him, and Terell was left bloody. Its difficult to argue against the roar of the crowd immediately after the bell of the 15th round, the photographers all being in Chuvalo's corner, and the crowd booing immediately after the announcement of the decision. Also, watch how Chuvalo's manager attempts to reach for the microphone as soon as the decision took place... the ring announcer pulls it away. Looks like Chuvalo's manager had something important to say... Again, these are not people who own a video, but were there.