What is the test for reducing criminal charges to misdemeanors at a preliminary hearing?

The People argued that People v. Silva (1995) 36 Cal.App.4th 231, [43 Cal.Rptr.2d 8] makes it very clear that once the court issues a bindover at preliminary hearing it loses jurisdiction to ... reduce [the charges] to misdemeanors prior to the adjudication. The People stated that [a]t this point the defendant has to plead a felony, and the court in its sentencing discretion can ... reduce it to a misdemeanor, but the court does not have the option to take a plea to a misdemeanor at this point in the proceeding because the defense did not make the motion at the appropriate time.

[181 Cal.Rptr.3d 905]