In 1989 I caught one the exact same way. It was also really young. I kept it in a cage for a couple days, feeding it raw meat, and then started taking it outside, with no tether. The third time outside it flew off. I guess that's when it was ready to go. It never occurred to me that something might have been wrong... I just assumed it was really young and wasn't quite strong enough to fly, yet. And I didn't want the dogs to get it.
You did a good thing.
I couldn't seen any injuries that jumped out at me so he could have just been exhausted. Since its a young bird it might just suck at hunting and wasn't able to eat.
Dog are a huge reason I picked this one up. We have so many feral cats/dogs, coyotes, foxes, and people pets running around its not even funny. Life can be hard for animals out in the country....
I just wish we had more hawks around to take care of the poisonous snakes!
