A trial by judge is very different than a trial by jury. In a jury trial, the only evidence that exists is the evidence that is presented in open court. Making a decision before the courtroom phase of the trial would be irresponsible.
But in a non-jury trial, the judge studies all the evidence independently, and the courtroom phase is just supplemental. You don't need someone to testify to the facts in their report if you can just read the report, right? The courtroom phase is also quite expensive, which is why a judge would indicate that based on the evidence she had seen, it probably wasn't worth doing it. To save everyone the effort.
But in a non-jury trial, the judge studies all the evidence independently, and the courtroom phase is just supplemental. You don't need someone to testify to the facts in their report if you can just read the report, right? The courtroom phase is also quite expensive, which is why a judge would indicate that based on the evidence she had seen, it probably wasn't worth doing it. To save everyone the effort.