A commenter pointed this article out to me.  I liked it.

Think about it. Anyone who says he or she routinely engages in defensive medicine is admitting that they practice outside the standard of care. They admit that they routinely engage in conduct that is, by definition in every state, medical malpractice. Indeed, they are admitting that in their discussion with the patient about the next step to take in their health care, they are lying when they disclose the risks and benefits of the proposed treatment.

Second, any doctor who admits they engage in "defensive medicine" is admitting they are engaging in insurance fraud. Yes, that's right, insurance fraud. A health insurance company is generally bound by contract to pay only those claims that are reasonable and necessary to treat illness or injury. The practice of "defensive medicine" is, by definition, an admission that two people are being lied to and victimized by fraud: the patient and the insurance company. (Either that or the patient and doctor are conspiring to defraud the insurance company.)

The only objective, rational way to know whether "defensive medicine" is being practiced is to look at a patient's actual medical records and have that care reviewed by other "reasonably prudent physicians." This is never done. A doctor who says "I practice defensive medicine (i.e. I lie to the patients and defraud the insurance company) never says "and here are my records to prove it." How could they? They would go to jail.

Source: The High Cost of Defensive Medicine | Benjamin W. Glass, III & Assoc. PC

I’d also like to see a doctor who claims he practices defensive medicine testify about that in a criminal prosecution or a medical malpractice trial.