A physician presented his bill to the attorney representing a deceased person's estate.  Each of them knew the other, having tangled quite a few times in court, where the doctor was often called as an "expert witness."

The Doctor asked the lawyer if he wanted the bill sworn to.

"No," replied the lawyer, "the death of my client is sufficient evidence that you attended him professionally."

"Be that as it may," replied the doctor, "the fact that you handled his affairs is probably why he couldn't afford to pay this bill in the first place."