The bad thing these days is that with any CMG, you really need to make sure you don't burn bridges and piss someone off when you exit. I've always bent over backwards to make sure no feathers were ruffled when I changed jobs. These guys can burn you and blacklist you and because they control so many job sites, can seriously affect future employment. I know one doc in the area that sued a CMG (not Apollo) for not paying him money owed when he left. (This is through another person, I don't know the details and did not know this doc personally) and was reportedly blacklisted at all of their sites. They took over a contract in town where he was working and he had to leave because they wouldn't contract with him.
I really hope this guy thought long and hard and got legal input before reporting the EMTALA violation. That kind of whistleblower suit does not go unnoticed among the CMGs and is another reason I'd expect him to find employment opportunities limited in the future.
My philosophy working for these corporate giants is very much like it was in residency. Keep your head down, don't cause waves, work hard and keep your mouth shut. Make hospital admin happy and make your FMD look good. Hide in the middle of the metric bell curve. Don't be an outlier and draw too much attention to yourself. All these things are good for job security. Sad, but true.