What is the role of the trial court in reviewing an order of the magistrate pursuant to section 995 of the Penal Code?

The function of the trial court in reviewing an order of the magistrate made pursuant to section 995 is stated in People v. Heard, 266 Cal.App.2d 747, 749--750, 72 Cal.Rptr. 374, 375--376:

'However, in considering a motion to dismiss under Penal Code section 995, the superior court is sitting as a reviewing court and is bound by the rules enunciated in Perry v. Superior Court, 57 Cal.2d 276, 283--284, 19 Cal.Rptr. 1, 368 P.2d 529: 'Although the magistrate, in reaching his decision (to hold an accused to answer following a preliminary hearing), may weigh the evidence, resolve [21 Cal.App.3d 867] conflicts, and give or withhold credence to witnesses, Such a balancing of the evidence is not within the powers of a tribunal reviewing the magistrate's order. (Citation.)' (Italics added.)

The propriety of this rule is particularly apparent when, as in the instant case, the superior court sitting as a court of review under Penal Code section 995 is asked to consider a terse and limited record of a preliminary hearing involving an issue that may be relitigated in a full and adversary hearing either at the time of trial or at a hearing upon a defendant's motion to suppress evidence under Penal Code section 1538.5. As aptly stated in Badillo v. Superior Court, 46 Cal.2d 269, 271--272, 294 P.2d 23: