Do not argue with Counsel; “disagree without being disagreeable.” “A large experience is not all experience,” and what you call “a rare case” may reflect upon your limited experience.
An early “I don’t know” is better than a late “I did not know.” If you “don’t know,” do not be trapped into guessing. Beware of “argumentative figures.”
The Matter.
If unable to decide as to the cause of death without a post-mortem examination, tell the jury so at once; the most experienced pathologist will do so the most often. Thus you may tell them, by way of apology, that any organ of the body may be ruptured without external signs of injury being apparent.
Distinguish what you have been told from what you have found by personal examination.
A knowledge of the facts differs from a knowledge of the records of those facts.
State what you knew professionally as to the health and the habits of the deceased, but do not condescend to detail; it is sufficient to say, “I treated him,” or “I prescribed;” you need not specify how unless required so to do.
Don’t offer any explanations unless directly asked; decline to give “expert opinion” testimony unless you feel fully competent so to do.
The jury value evidence by the exactness of statement of, and the powers of observation evidenced by, a witness. Little benefit is gained by cross-examining one who is obviously telling the plain truth.
Don’t exaggerate or estimate—“blessed are the pure in fact” in a law court; in measurements and descriptions be accurate, quoting figures where possible.