video of seaworld trainer dawn brancheau performing with tilikum, a spectacular killer whale.e down together in shallow water and then something goes terribly wrong. >> this whale grabbed her, pulled her in the water. >> reporter: tilikum, the 12,000-pound 22-not-long killer whale kills the 40-year-old trainer igniting a controversy that is still playing out today. it's fuel for a bitter back and forth between seaworld and this documentary filmmaker, gabriela cowperthwaite, her new documentary, "blackfish" out today raises the troubling question, can or should killer whales be held in captivity. >> i didn't understand why a killer whale would bite the hand that feeds it. you know, his trainer. >> reporter: but now the film has seaworld going on the offensive. seaworld told abc news in a statement "instead of a fair and balanced treatment of a complex subject, the film is inaccurate and misleading and regrettably exploits a tragedy that remains a source of deep pain for drawn brancheau's family, friends and colleagues." seaworld also sent film critics an e-mail pointing out wha