When a jury retires to consider its verdict they must only rely on evidence presented in court.
Judges direct jurors to consider only what the witnesses said in court and documents, exhibits and for example video evidence admitted as evidence in court.
Judges go one-step further and direct jurors not undertake their own research, not to discuss the case with family and friends and therefore under no circumstances bring into the jury room material not presented as evidence in court. In this case one juror did bring into the jury room material resulting from research outside the jury room.
Once this came to light ACT Supreme Court Chief Justice Lucy McCallum brought the jury in and discharged them. To abort this trial after 5 plus days of serious jury deliberation is more than disappointing. A retrial is listed to begin in February 2023.