The 33-year-old was fighting three charges after an alleged incident at the Gungahlin Raiders Club last year, including intimidating police and refusing to leave a licensed venue.
But at an ACT Magistrates Court hearing on Friday, Chief Magistrate Lorraine Walker permanently stayed the case, meaning it will be dropped indefinitely, after finding police undermined the integrity of the prosecution by discussing the proceedings in a Signal chat.
Police alleged Papalii was behaving aggressively towards staff after being asked to leave the leagues club in Canberra's north during the early hours of September 16, 2024 after a night of drinking.
After police were called to the venue, he allegedly became verbally abusive and threatening towards officers and refused to leave the premises.
Papalii pleaded not guilty to the charges.
But the case was delayed when Papalii's lawyers discovered the existence of the private group chat on messaging service Signal, which included the officer who was the alleged victim of the alleged intimidation, as well as investigating officers.
Police are not prohibited from using encrypted messaging services like Signal to communicate in the ACT, although other jurisdictions do not allow it.
Defence barrister Steven Boland asked Ms Walker to issue a permanent stay of the proceedings, meaning the case would be dropped indefinitely.
Mr Boland argued the officers' use of the Signal chat to discuss the case, which was set to automatically delete messages after one week, constituted an abuse of process and would bring the administration of justice into disrepute.
As messages relating to the case could have been automatically deleted, it meant the prosecution's duty to disclose evidence pertaining to the proceedings could not be met.
The conduct was "sufficient to bring the administration of justice into disrepute and erode public confidence in it", the defence submitted.
The prosecution argued there was no evidence of messages in the group chat detailing information that would have materially changed the course of the proceedings.
There was thus no evidence that by not keeping a record of the messages, it would have been materially unfair to the defence, prosecutors argued, calling for a lesser remedy than a permanent stay to be applied.
The chief magistrate said while there was clear evidence that Signal was used by the investigating police to communicate about the investigation, the defence was unable to establish the deletion of the messages left them at a practical disadvantage.
But the unknown remains unknowable, she said, and the "cavalier" use of Signal by the officers raised the spectre that additional communication that was unfair to the prosecution may have occurred.
"Allowing the prosecution to proceed … is an irremediable affront to the integrity of the process," she told the court.
"A permanent stay of the prosecution is granted."
