Can a motion for pretrial discovery be made after the first witness has testified at the preliminary hearing?

Petitioner relies upon Saulter v. Municipal Court, 75 Cal.App.3d 231, 142 Cal.Rptr. 266, wherein defendant, after the first witness had testified at the preliminary hearing, sought an order requiring the prosecution to furnish him with certain federal and police department records. The motion was denied and the court suggested that he attempt to secure the records by subpoena duces tecum. As to the federal records, the subpoena duces tecum was issued. The matter was then continued to allow federal authorities to comply with the subpoena. On appeal, it was held that the trial court erred in denying defendant either an order or a subpoena for the production of the federal records without first requiring the prosecution to request the records. However, the court also criticized the way the proceedings in the case ensued. It stated that defendant's supplemental motion for pretrial discovery could have been denied on the ground that it was untimely. Also, the preliminary hearing should not have been stayed since defendant would not have been prejudiced had the preliminary hearing proceeded on the assumption that the incidents of which complaint had been made in the reports had occurred, without prejudice to the defendant's right to renew his motion in the superior court.