The Great White Shark was thought to be the apex predator of the sea but now that's challenged. Orcas or Killer Whales appear to be a formidable foe to the Great White as during observations in Great White feeding grounds they were seen to flee when their feeding grounds were infiltrated by Orcas even though the Killer Whales were just passing through.
Science often has to rewrite the rules when presented with conflicting information and this might be one of those cases.