Closing gates have proven problematic in the past at SeaWorld parks. In 1995, a large bull named Kotar was "playing" with a metal gate when it closed on his head, fractured his skull, and subsequently killed him. On September 8th of 2014, Kotar's pregnant 9-year-old granddaughter, Kalia, was caught in an automatic gate, from which she was eventually released free of visible harm (Click here for video). In regard to Kalia, SeaWorld responded saying, "Gate play is nothing more than an enjoyable game for the whales, and something they've been doing for years. In the instances that whales are playing with a gate, they are always being monitored and supervised by several trainers." While the gates nowadays may be "low pressure," Kotar should not have been killed from playing with his own enclosure to fulfill his need for stimulation.
Despite Makaio's age and the fact that his mother was not too far away, killer whale mothers form lifelong bonds with their offspring. SeaWorld San Diego's matriarch, Kasatka, has acted aggressively with trainers following the separation of her calves. In 2006, Kasatka repeatedly dragged trainer Ken Peters to the bottom of the pool as a direct result of her daughter Kalia calling for her from an adjacent tank (Click here for video). Breaking a parental-offspring bond, even if temporarily, for the sake of a show does not contribute to the social health of these socially complex creatures.
Killer whales and other animals held in captivity should not be living in an abnormal environment full of potential hazards, nor should they be pushed into unnatural situations. Even though Makaio was not touched by the gate this time around, his decision was a bold one-and solidifies the artificiality of orca captivity.