When will a defendant be allowed to question an eyewitness at a preliminary hearing?

Jennings v. Superior Court, supra, 66 Cal.2d 867, 880, 59 Cal.Rptr. 440, 428 P.2d 304, holds a defendant at a preliminary hearing must be permitted, if he chooses, to elicit testimony or introduce evidence tending to overcome the prosecution's case or establish an affirmative defense. It is not a valid objection that examination of a witness may lead to the discovery of what the facts were. That is the very purpose of examining a witness. If the questioning is not otherwise objectionable, the court should allow reasonable latitude in the defense questioning of an eyewitness at the preliminary hearing.