It is the entry of a not guilty plea which actually begins the trial process, not the trial itself. A magistrate may commit for trial even after a not guilty plea has been entered but before the trial begins.
Citations:
Times 22-Feb-1996, Gazette 20-Mar-1996
Statutes:
Magistrates Courts Act 1980 25(2)
Criminal Practice, Magistrates
Updated: 09 April 2022; Ref: scu.86892