I'm a bit of an ornithology nut specializing in birds of prey. Can't get enough of them. Let me tell you Ariel, this is one * cool experience, and you caught it on film! NICE! Thank you for posting it.
Sorry gents, but this is definitely not a Harris hawk nor an eagle of any type.
I concluded this after reviewing your video over and over. To first counter the eagle ID, the size doesn't appear to be 3 feet judging against his prey and surrounding brush. He actually looks to me to be smaller (22-26" range) which, standing atop a duck, would indeed put him nearly 3 feet off the ground. An eagle would be 30-37" long w/o a duck under him.
Secondly, lets address the beak. His beak colors are in line with what I have seen and read about red-tails. But the dead giveaway is that an eagle's beak has a much larger profile vs. the head proportionately. Again, your video shows a proportion very much in line with a RTH and not an eagle as seen here.
An immature bald eagle
Your Raptor
Note the eye color as well. A harris hawk has dark brown Irises like this.
Note the color of the Harris which is quite distinctive as opposed to a RTH which is highly varied.
Red-tails as fledglings have pale yellow or straw colored eyes which turn darker brown when they mature.
To me, this is a juvenile red tailed hawk. My guess is he is probably happier to have a meal than he was scared of you! Congrats. I loved the video!