Perhaps because he was in a coma for two years they were projecting long-term. A week/ your grandma's surgery, that is one thing, a short objective. As a coma drags on and on and the doctors don't see improvement or hope, I imagine one sees it so differently.
Our understanding was that the length of time did not matter. She was on a floor with other patients who were also in comas..not due to surgery. In fact, we were there one evening when a young man, who had been in a coma for several months as a result of a motorcycle accident, "woke up". That is one of the reasons the nurses and such were so conscientious about telling us that people can hear in comas. We were visiting with families in the rooms of our various loved ones throughout the days. I really don't buy the idea that the Italian doctors didn't know this.