I can vouch from assisting with brain and spine surgery for 5 years, that it isn't brain surgery. I've seen alot of mishaps, accidents, things done the wrong way, and "incisions an 8th of an inch too far to the left." Just like flying, 99% of the time things turn out ok. When they don't, doctors are also usually only subject to getting "slapped on the wrist," or do a bit of supervised work. Not that it is insignificant, but when a doctor really messes it up, usually only one person dies. When pilots really mess it up, they take an airplane full of people with them. At least the doctors have malpractice insurance. Pilots are subject to having their estates picked apart by hundreds of angry family members with no insurance provided by the carrier.