“13. … But it is well settled that interested evidence is not necessarily unreliable evidence. Even partisanship by itself is not a valid ground for discrediting or rejecting sworn testimony. Nor can it be laid down as an invariable rule that interested evidence can never form the basis of conviction unless corroborated to a material extent in material particulars by independent evidence. All that is necessary is that the evidence of interested witnesses should be subjected to careful scrutiny and accepted with caution. If on such scrutiny, the interested testimony is found to be intrinsically reliable or inherently probable, it may, by itself, be sufficient, in the circumstances of the particular case, to base a conviction thereon. Although in the matter of appreciation of evidence, no hard-and-fast rule can be laid down, yet, in most cases, in evaluating the evidence of an interested or even a partisan witness, it is useful as a first step to focus attention on the question, whether the presence of the witness at the scene of the crime at the material time was probable. If so, whether the substratum of the story narrated by the witness, being consistent with the other evidence on record, the natural course of human events, the surrounding circumstances and inherent probabilities of the case, is such which will carry conviction with a prudent person. If the answer to these questions be in the affirmative, and the evidence of the witness appears to the court to be almost flawless, and free from suspicion, it may accept it, without seeking corroboration from any other source. Since perfection in this imperfect world is seldom to be found, and the evidence of a witness, more so of an interested witness, is generally fringed with embellishment and exaggerations, however true in the main, the court may look for some assurance, the nature and extent of which will vary according to the circumstances of the particular case, from independent evidence, circumstantial or direct, before
