Lawfag here, this was very unusual, at least for my home jurisdiction. I don't know about Wisconsin, but jurors are NOT allowed to conduct their own research on the LAW. The jury is to determine which facts are true based on the evidence presented at the trial. Any questions the jury has about the law (which is what jury instructions are) MUST be asked to the judge. Most times a jury foreperson would write down a question, give it to the Marshal or Sheriff in charge of the jury, who gives it to the judge. The judge calls the attorneys involved into chambers, tells them there is a question(s), then calls all parties into the courtroom, calls in the jury, then answers the questions in the courtroom and on the record. Short answer: jury decides facts, the judge determines the appropriate law for the case. This may be reversible error on the part of this judge, but I hope it does not go that far.