I think I've mentioned these before - just a couple of examples I know about:
1) Friend's step father: Had some serious discomfort in his chest when breathing. Dr. had X-rays taken. Diagnosis - lung cancer. Rapidly-scheduled surgery that involved a 4-foot long incision that wrapped around his back, etc. Lots of pain, lots of pain meds, lots of recovery time. Undoubtedly, lot of expense for his insurance policy and/or Medicare. Pathology report on the stuff removed: scar tissue from old lung infections, not cancer.
2) Father in law temporarily in a nursing home for rehab after a brief hospitalization to install a trache tube to ease his breathing. After a day or so, he was nearly comatose. The nurses and aids talked about how great he was doing - "See, he can touch his face with a wash cloth!", as he sat in a wheel chair and did almost nothing. Turns out, they were crushing his time-released morphine pills and giving them to him with his other crushed medications. So rather than getting, say, 30 mg of morphine over 8 hours, he was getting it over a few minutes. And that was one of the better nursing homes around here...
One often hears stories of surgery nearly being done on the wrong leg, though apparently operating rooms are getting better at using markers to make big X's and say "Other Leg!" and similar...
I've also heard several stories from friends over the years who said that nurses had killed patients sharing their room by giving them the wrong meds, or the wrong dose. I'm sure its relatively common (as the SFC story points out).
You're right that everyone who is hospitalized needs an individual advocate. It's too easy for mistakes to be made, too often with serious or deadly consequences.
Cheers,
Scott.