Prosecutors have dismissed claims that housing the jury in the same hotel as police and prosecutors during deliberations was a "catastrophic failure" and urged the court to reject Erin Patterson's bid to overturn her murder convictions. Patterson, who was sentenced to life in prison with a non-parole period of 33 years on September 8, appeared in the Supreme Court of Appeal via video link on Thursday.

Her barrister, Richard Edney, argued on Wednesday that a "fundamental irregularity" occurred during the jury's sequestration, which he contended fatally undermined the integrity of the verdicts and warranted a retrial. "We would describe the sequestration and what occurred during it as catastrophic," Edney told the court, asserting that the jury's placement in a hotel alongside journalists, police, and prosecutors was unfair.

Director of Public Prosecutions Brendan Kissane KC countered that there was no evidence to support the claim. "Far from being some sort of catastrophic failure, there’s no evidence in our submission to support this ground," Kissane stated. He argued that the system functioned as intended, with sworn jury keepers reporting no interaction between the jurors and any other individuals.

Kissane emphasized that the core issue was whether communication occurred between the jury and others. "The evidence as it stands points towards there being no communication, and once the court accepts that, then there’s no irregularity in this situation, let alone a fundamental irregularity that goes to the root of the trial," he said. He dismissed the notion that merely sharing a hotel entrance or the possibility of jurors glimpsing someone through a window constituted improper contact, clarifying that the concern was directed at actual communication.

During deliberations for the high-profile death cap mushroom trial, the jury was sequestered at a hotel in the Morwell area. Members of the prosecution team, reporters, and a key police witness were also staying at the same hotel for a period. Prosecutors acknowledged that the arrangement was "obviously undesirable" and that the trial judge would likely have prevented it had he been asked in advance. However, Kissane stressed that the situation arose "accidentally" due to limited local accommodation and that no actual irregularity took place.

"There’s no evidence whatsoever that any member of the jury spoke or had the opportunity to speak to any other person apart from the jury and the jury keeper. Let alone anyone from the prosecution team," Kissane told the court. Prosecutors argued that a fair-minded observer, aware of safeguards such as separate dining, continuous supervision by sworn keepers, and the jurors' own oaths, would not conclude that anything had gone wrong.

The appeal hearing was scheduled to continue, with prosecutors also expected to argue that Patterson's sentence was "manifestly inadequate."