It is well to note that, as stated by the Court of Appeals, Jose Sebastian was originally a witness for petitioner Augusto. As such, Rule 132, Section 12, of the Rules of Court prohibits petitioner from impeaching him:
SEC. 12. Party may not impeach his own witness. – Except with respect to witnesses referred to in paragraphs (d) and (e) of section 10, the party producing a witness is not allowed to impeach his credibility.
A witness may be considered as unwilling or hostile only if so declared by the court upon adequate showing of his adverse interest, unjustified reluctance to testify, or his having misled the party into calling him to the witness stand.
The unwilling or hostile witness so declared, or the witness who is an adverse party, may be impeached by the party presenting him in all respects as if he had been called by the adverse party, except by evidence of his bad character. He may also be impeached and cross-examined by the adverse party, but such cross-examination must only be on the subject matter of his examination-in-chief.
This rule is based on the theory that a person who produces a witness vouches for him as being worthy of credit, and that a direct attack upon the veracity of the witness “would enable the party to destroy the witness, if he spoke against him, and to make him a good witness, if he spoke for him, with the means in his hands of destroying his credit, if he spoke against him.”
Neither had there been declaration by the court that Jose Sebastian was an unwilling or hostile witness. Jose Sebastian is also neither an adverse party, nor an officer, director nor a managing agent of a public or private corporation or of a partnership or association which is an adverse party.
Be that as it may, even if Jose Sebastian had been declared by the court as an unwilling or hostile witness, the third paragraph of Section 12 as quoted above, in relation to Section 11 of the same Rule, only allows the party calling the witness to impeach such witness by contradictory evidence or by prior inconsistent statements, and never by evidence of his bad character. Thus, Jose Sebastian’s subsequent dismissal as a judge would not suffice to discredit him as a witness in this case.
(E)ven convicted criminals are not excluded from testifying in court so long as, having organs of sense, they “can perceive and perceiving can make known their perceptions to others.”
The fact of prior criminal conviction alone does not suffice to discredit a witness; the testimony of such a witness must be assayed and scrutinized in exactly the same way the testimony of other witnesses must be examined for its relevance and credibility. x x x. (Emphasis supplied.)
The effect of this pronouncement is even more significant in this case, as Jose Sebastian has never been convicted of a crime before his testimony, but was instead administratively sanctioned eleven years after such testimony. Scrutinizing the testimony of Jose Sebastian, we find, as the trial court and the Court of Appeals did, no evidence of bias on the part of Jose Sebastian. On top of this, Jose Sebastian’s testimony is supported by the records of the notarial registry, which shows that the documents in question were received by the Notarial Registrar on2 July 1979, which was four months before the death of Consuelo on6 November 1979.