Check out the film Mama/M.A.M.A.
It is exactly the ill-defined nature of Munchausen Syndrome by Proxy that makes it an accurate description of the behavior of Terri Schiavo's parents. I think your observation is on the money but if you want to see a good criticism of the diagnosis, check out the documentary Mama/M.A.M.A. As the Roy Meadow story indicates, there are some serious flaws with how this fluid diagnosis has been applied. Mama/M.A.M.A has the last known interview with Meadow which was used by the BBC.
