Anyone ever heard of this?

For the last few weeks, Man has been going to physical therapy for something wrong with his shoulder. It wasn't until just a couple days ago that the physical therapist has begun to understand the exact nature of this condition. Man showed me last night. He took off his shirt and started to do a pushup against the wall. His right scapula stuck out from his back by a good 3-4" while his left scapula just sort of stayed stuck to his back. What is it? What does it mean? We have no idea but he has some exercises he has to do to try and strengthen his muscles so that his bones will stay put and quit pinching and inflaming the muscles in his shoulder.

Has anyone had any experience with this at all? We're absolutely at a loss except for the exercises he's been prescribed to "try" to make it better. Fortunately (no, really) he's still able to sprint and ruck march (which is a really fast (5 mile?) run at the end of which they pick up at least 60 pounds of gear and march at a quick pace all the way back).