When a great white shark lunges and bites something, it is temporarily blinded. They also cannot swim backwards. So this shark lunged at the bait, accidentally hit the side of the cage, was most likely confused and not able to swim backwards, it thrust forward and broke the metal rail of the cage. There was a single diver inside the cage. He ended up outside the bottom of the cage, looking down on two great white sharks. The diver is a very experienced dive instructor, remained calm, and when the shark thrashed back outside the cage, the diver calmly swam back up and climbed out completely uninjured.
Kudos to the diver for remaining calm. That’s more than we could’ve done. 