I've had 2 relatives who were submitted to different local hospitals for different things, but they both contracted secondary infections, which nearly killed one of them.
At the end of the day, we should feel lucky that a complete stranger made an honest effort to help you or your loved one in their time of need, and not focus exclusively on the complications and accidents that may have happened along the way.
To anyone who works in healthcare, if you don't already, I would strongly encourage the use of checklists for any and every important task. Checklists save lives. [0]
[0] http://www.who.int/bulletin/volumes/86/7/08-010708/en/
http://news.bbc.co.uk/2/hi/health/7825780.stm
http://www.hsph.harvard.edu/news/magazine/fall08checklist/
Edit: Typo.
Edit 2: These hospital visits were covered by Canadian healthcare so we didn't have to pay hundreds of thousands of dollars. I can see how it would be very difficult to overlook complications and accidents when the bill will likely bankrupt you.