I was also thinking about this when watching Sicko, Moore obviously didn't read the newspapers about NHS cuts, the junior doctors, hospital closures, NHS not performing well etc. whilst he was in England at the time.
However, he's only trying to put over a point to the Americans that a free health care system works. You have to agree that mentioning all the current flaws of the NHS are hardly going to win american approval.
Anyways, Fahrenheit 9/11 was entertaining yet factual, congruous to the Moore style of documentary.