Is it prejudicial error for the court to admit this rebuttal testimony?

It was prejudicial error for the court to admit this rebuttal testimony since it went far beyond the permissible bounds of attacking a witness' credibility. When a witness is cross-examined for the purpose of destroying his credibility by proof of specific acts of misconduct not the subject of a conviction, the examiner must be content with the answer. The examiner may not, over objection, produce independent proof to show the falsity of such answer. United States v. Sweeney, 3 Cir., 1959, 262 F.2d 272, 276-277.