What legal idioms mean to you

"Do you know where 'let the cat out of the bag' came from?" asked my patient, with a grin. Sitting in my clinic office, he wasn't demonstrating tangential thought process, just setting me up for my next lesson in idioms.

"It came from England, where pigs were sold in the marketplace and placed in burlap bags for transport," he continued. "Crooked salesmen would substitute cats for the pigs after the sale. The unsuspecting customers would return home to find they'd been swindled -when the cat was let out of the bag!"

Mr. Smith (not his real name) had written the book on idioms-literally. During my three years as his physician, I discovered how ubiquitous these expressions are in the English language.

As in medicine, a myriad of idioms litter the American legal system-phrases like "brush with the law" and "throw the book at him." But in the courtroom, one expression stands apart: that literal, unambiguous query, "Do you swear to tell the truth, the whole truth and nothing but the truth, so help you God?" Posed to me twice in recent months, this simple question asked of anyone who is about to give legal testimony truly "hits home."

Should I play the role of "hired gun"?

I "took the plunge" into the pool of medical litigation when I was asked to serve as an expert witness. But before I agreed to testify, I sought advice from senior faculty members at my teaching hospital. Some thought I should pass on the job. One said he "wouldn't touch it with a 10-foot pole." Others, including my chairman, thought it would provide an excellent education in the medico-legal process-a subject our medical schools devote little or no time to despite malpractice's status as every physician's "Achilles' heel."

My role as an internal medicine/psychiatry expert was to review a case on behalf of a physician I'll call Dr. Jones, who had been practicing medicine for nearly as long as I've been alive. He'd seemingly been pulled "out of the frying pan" of his busy practice and thrust "into the fire" of litigation. I read through his deposition, starting with: "Do you agree to tell the truth . . ." It proved a fitting preamble to a series of unforgettable lessons.

The plaintiff was a patient committed to a psychiatric hospital for evaluation and treatment of psychosis. At the nearby community hospital, police officers had to wrestle him to the ground because of his erratic behavior. Once in the psychiatric facility, he allegedly hallucinated and hit his head against a metal-grated window in a seclusion room. Dr. Jones, a consulting internist, was summoned after the patient refused to get up off the floor. His preliminary diagnosis: hysterical paralysis. The intervention: intramuscular normal saline. After the patient lay on the seclusion room floor for two days, the diagnosis was changed to quadriplegia secondary to cervical fracture. The intervention: neurological surgery.

Trying not to play "Monday morning quarterback," I learned three valuable lessons from this case-lessons that have made me a better physician and clinical educator.