Can a defendant's explanation given in answer to a prosecutor's question be challenged?

Defendant's explanation given in answer to the prosecutor's question was never challenged. Since defendant admitted to possessing the child pornography, the admission of Doe 5's allegation could not have been prejudicial to his conviction on count 30 (possession of child pornography). Given the overwhelming evidence of defendant's guilt on the remaining counts, it is not reasonably probable the jury would have reached a more favorable verdict as to any of the counts had the testimony been excluded. (People v. Watson (1956) 46 Cal.2d 818, 834.)