I have been raising birds for almost 5 years. I have learned that death is part of life with birds. Babies are fragile and some don't make it.
One time I did the same as you, only it was a conure who fell out of my hands and that minute I moved forward and sure enough, I stepped on him. He died in minutes. It was horrible and it all happened right in front of a customer. Then I had to tell another customer what happened as she had a deposit on that bird.
I have dealt with alot of painful losses raising birds and somehow I have learned how to deal with it as part of the whole thing. I can't let it completely tear me up each time or I would not be doing this any more. There is far more good things and joys that take place.
I have been reading here alot and it seems that it is this way with chickens too. People are reporting losses to predators, losses to new shipped babies and much more.
I guess we gotta get tough some how if we are going to survive being chicken parents.
Say a little prayer for your guy and trust God he is ok. I doubt he is going to have a problem as birds don't have very wide necks and if you would have broken it, that is instant death for them. It sounds like he hurt when it happened, but he has sprung back.
Give him some special treats and attention and maybe he will become your best friend.
Lovin my chickens. Terry