Review first published by Film4. Synopsis: Gabriela Cowperthwaite’s documentary casts a wide net in determining why a captive orca killed an experienced trainer at SeaWorld Orlando. Review: If Michael Anderson’s Jaws-riffing Orca (1977) paints killer whales as implacable underwater avengers, while Marine Mammal Parks would prefer us to see orcas as cuddly clowns that just…