Medicine/Rehab is not, surprisingly, an exact science. The sports world is littered with stories of players who have tried different approaches than had been prescribed by club staff, and have had better results.
Tony Adams and Mike Atherton spring to mind.
Then there is that German knee surgeon who seemed to use witchcraft to mend some players. Cant recall his name.
I know a few guys down here who work in the Rugby world. They are always looking at different methods and treatments that both get players back quicker, but also aim to prolong careers.