[Pseudoscience-is-malarkey (OP)]

A senior British Suba diver recounts an experience where she was saved by a giant orca from a shark. I think she might be just assuming that the whale was protecting her. I think the whale was just playing with her and expressing it's curiosity, and the proximity of the shark was coincidental. The vast majority of sharks will not eat a human, as they're not part of their diet. And despite their ranking as "apex predator", they are wary of humans.