Yup, start with a very young bird with little to no real world experience, pop a hood on him so he has no idea what is going on around him, along with a level of stress so overwhelming he simply shuts down....yup, bird sure looks calm.
And you take advantage of that confusion and ignorance to teach the bird you are the source of everything good and wonderful (food, more food, and yet more food), pretty soon you are about the coolest thing this bird has ever met! In fact, you are so cool it's just not worth the effort getting scared when you walk into the room. So very cool the risk of flying towards a predator 75X bigger than you is outweighed by the reward of food....and later flying time!
When they show that level of trust with you, it's pretty amazing. Some falconers forget what the early days are like and get that ridiculous mindset of "just a redtail". I hope your buddy never catches that disease because it will steal almost all of his joy and poison what little is left.
Nine plus years I have been working with raptors and I still get dust and stuff in my eyes when our new redtail starts to chirrup and peep at me when I walk around the corner. Heck, I'm getting something in my eyes thinking about our 30 yr old redtail that used to hate me, then loved me, hated me again and sunk talons in my face, then tolerated me and now hates me all over again.