-389§ 2867. Effect of error in overruling claim of privilege A party may predicate error on a ruling disallowing a claim of privilege only if he is the holder of the privilege. Subchapter VI—Extrinsic Policies Affecting Admissibility § 2891. Evidence to test a verdict Upon an inquiry as to the validity of a verdict no evidence shall be received to show the eflfect of any statement, conduct, event or condition upon the mind of a juror as influencing him to assent to or dissent from the verdict or concerning the mental processes by which it was determined. § 2892. Testimony by the judge Against the objection of a party, the judge presiding at the trial may not testify in that trial as a witness. § 2893. Testimony by a juror A member of a jury sworn and empanelled in the trial of an action, may not testify in that trial as a witness. § 2894. Testimony of jurors not limited except by this chapter This chapter does not exempt a juror from testifying as a witness, if the law of the Canal Zone permits, to conditions or occurrences either within or outside of the jury room having a material bearing on the validity of the verdict, except as expressly limited by section 2891 of this title. § 2895. Discretion of judge to exclude admissible evidence Except as in this chapter otherwise provided, the judge may in his discretion exclude evioence if he finds that its probative value is substantially outweighed by the risk that its admission will (1) necessitate undue consxunption of time, or (2) create substantial danger of undue prejudice or of confusing the issues or of misleading the juiy, or (3) unfairly and harmfully surprise a party who has not nad reasonable opportunity to anticipate that such evidence would be offered. § 2896. Character; manner of proof When a person's character or a trait of his character is in issue, it may be proved by testimony in the form of opinion, evidence of reputation, or evidence of specific instances of the person's conduct, subject, however, to the limitations of sections 2897 and 2898 of this title. § 2897. Character trait as proof of conduct Subject to section 2898 of this title, when a trait of a person's character is relevant as tending to prove his conduct on a specified occasion, such trait may be proved in the same manner as provided by section 2896 of this title, except that (1) evidence of specific instances of conduct other than evidence of conviction of a crime which tends to prove the trait to be bad shall be inadmissible, and (1) in a criminal action evidence of a trait of an accused's character as tending to prove his guilt or innocence of the offense charged, (A) may not be excluded by the judge under section 2896 of this title if offered by the accused to prove his innocence, and (B) if offered by the prosecution to prove his guilt, may be admitted only after the accused has introduced evidence of his good character. § 2898. Character trait for care or skill; inadmissible to prove quality of conduct Evidence of a trait of a person's character with respect to care or skill is inadmissible as tending to prove the quality of his conduct on a specified occasion.