Verification of signatures of other doctors-Can we just stop there?

At times, a doctor, as an expert witness, has to depose on facts observed by another doctor. The spectrum for such evidence may extend from just identification of the signatures of his colleague, to even furnishing expert opinion based upon facts observed by him; who now happens to have left the institution, or is untraceable, or summoning him to the witness box would entail large amount of funds. Legal stand on such expert evidence seems to be ambiguous, even though, now, both the Hon'ble Supreme Court and the High Courts have decreed that when called upon to do so, the expert witness is to give opinion based on facts observed by his colleague, provided these facts have been agreed upon by both the prosecution and the defense and that they have been admitted by the court. The position of the various laws and the outlook of the courts is discussed in this editorial.