What is the effect of defendant's objection to a police officer's testimony that the officer had conducted a live lineup?

As the court stated in overruling defendant's objection, defendant's question whether the officer had conducted a live lineup opened the door to questions about why he had not. Defendant's question did raise an inference that the officer's investigation was incomplete and the prosecution was allowed to rebut it. (People v. Matthews (1980) 108 Cal.App.3d 793, 795.) Nor can the officer's testimony be categorized as an opinion. Rather, the officer explained how he had conducted his investigation. More importantly, the witnesses identified defendant in court. These brief statements by the officer, in light of the other evidence, were not particularly significant. Finally, the court gave a limiting instruction right after the testimony was elicited and gave another shortly after that. Admission of the statements was not erroneous.