You might want to pause it at 6 seconds; after that it gets a bit irrelevant (unless escaped Eagle Owls have set up a pension fund).
But, just to add some weight to argument against "birds without jesses etc (possibly) being of wild origin"; as if all the proper scientific stuff in British Birds wasn't enough:
I was sent some images this afternoon by my granddad of an Eagle Owl at The Barn Owl Centre in Gloucester.
He's called Kaln and flies without jesses, rings, &c, which makes him a delight for those professional photographers who prefer 'controlled' situations.So there you go—an Eagle Owl of known (captive) origin with no physical signs of captivity. Food for thought.