Just watched it. It was very interesting. Although I wish there was more footage of the orca attack.
The fact that the smell of the death of a great white shark is so repellent that it shocks a shark out of tonic immobility tells me that there was probably something in the ocean, prior to these orcas that was so bada$$ that its presence was encoded into the genetic memory of sharks. I mean, anything that can kill an adult gw shark is nothing to be played with.
It might STILL be in the ocean and we just don't know about it.