A prosecutor attempts to lay charges against an alleged perpetrator (in New Zealand anyone can do this under the private prosecution provisions).
The judge is presented with a set of pieces of circumstantial evidence and has to decide whether they are sufficient to justify a trial. If they are, he issues summons to the defendant and the process kicks off. If they are not, he drops the charges.
Any one of those pieces of evidence in isolation cannot prove guilt beyond reasonable doubt. However, looking at them all together one can see that they corroborate and draw inferences of fact. Such inferences can well be sufficient to prove criminal charges.
The judge considers only some of the pieces of evidence, not all, and drops the charges saying that there was no direct evidence. He does not explain why the rest of the evidence was not considered.
Is this an error of law, or any other judicial error?