The judge wouldn't have known what a Tor node is—but that's not a bad thing. What he's saying here is that the facts as originally presented to him translated into a well-known "cached" judgement; but the facts as they actually were would require original thought and research on his part (and/or those of analysts working for the judge) to come to a decision. "Guy has child porn on his computer" has a clear-cut answer; "open proxy server contains child porn" is indeed much
less clear-cut. What the law says about that subject is murky; hazy, even. It's something you would need to think about.
And this thinking is, in practice, what the vast majority of a judge's every-day job is: to Do The Research—to become experts in the things they're asked to rule on, to build up the context necessary to discriminate between assertions made to them by opposed parties. Judges are already experts on the law; but that only helps when the law is already so well-established that a judge isn't even necessary. In most cases, the law is vague: it doesn't already have the answer for what should happen in this particular case, with these particular facts. The point of the judge is to decide what the law should be—to gather facts about the world, and use them to answer a question in a way that sets legal precedent going forward.
Everyone else in the court's job is, then, to feed the judge all the necessary facts about the case, on both sides, so that the judge can know just what subjects must be made clear—must be researched, or questioned, or followed up on—before the case can be decided.
(Even the irrelevant statements; the judge is the one expected to know what the law must blind itself to, so the judge wants to hear everything, and then cull the pile of statements themselves. When a jury is present and must be the one to decide, the judge will attempt to moderate the jury using this same legal-blinding... but with mixed results. In jury trials, you'll see judges trying to keep attorneys from making certain assertions that might irreparably bias a jury; but in non-jury trials, judges just want all the information they can get.)
In short: as long as judges are doing their jobs, the law keeps up. That's what we pay judges to do. If the law isn't keeping up, we've just hired some bad judges.