I bet next time, if there is a next time, the eagle will pick a smaller target, make sure he hits it with a kill stroke, and is able to pull his tallons/claws free if required.

Having suffered such falls as were shown, I don't like his chances of flying off, birds bones are usually hollow to save weight, but give up strength because of it.

A bird, even an eagle, is limited to his lifting power, and I think this ones eyes were bigger that his stomach, and even at double flap speed that was beyond his lifting capacity.
Hope he lived to try again.