In fact, you can fracture your larnyx or Adam's Apple, and I'm very glad that, if your friend did so, he isn't dead.
You see, breaking the larnyx can, and often does in serious cases, lead to swelling that can completely block the airway. The person can suffocate.
In serious cases, the larnyx has to be fixed in place with a metal plate to allow it to heal right. As it heals, the victim must be intubated so he can breathe.
Obviously, your friend has not had that bad an impact on his larnyx, for which you both can be very grateful.
Get him to a doctor, and tell him NOT to move it. You wouldn't want him to make the break worse, if it is his larnyx. Go now.