After hearing all of the evidence and the addresses, the Magistrate has the duty (without referring to anyone else) to decide whether the defendant is guilty. The magistrate may adjourn the case to consider whether the defendant is guilty or not, but in many cases the decision is given straight away.
If there is any reasonable doubt about whether the defendant is guilty, the defendant is given the benefit of that doubt and found not guilty, the charge is dismissed.
If satisfied beyond reasonable doubt that the defendant is guilty, the magistrate will find the charge proved and will then consider what penalty should be imposed, see The Sentencing Process (and following sub-sections discussing the matters affecting sentences etc).