Is it possible to train a hawk to PROTECT birds like macaws and youcans from other birds of prey?

I heard some animal trainer guy in California was tired of having his birds attacked by birds of prey when he trained his chicks to free flight so he took some scarlet macaw eggs, toco toucan eggs, and a legally obtained red-tailed hawk and raised them all togheter as well as with a bunch of other birds he was training. He worked with the hawk NOT to attack the birds and the one time he had was training some military macaws and he had his hawk there. An owl attempted to attack one of the macaws and BAMM! the attacked the wol and nudged the macaws back to the trainer. Is this true or is this just another impressive fairy tale from Hollyweird? Or more importantly, could it be done? And no, I'm not crazy enough (yet) to do so and I won't be getting my hands on a animal broking license or a zoo license any time soon yet, but we all ask things (somewhat) like this every once in a while, right?