A Salvation Army officer accused of abusing four boys in the same training centre was acquitted when evidence was disallowed, a national inquiry has been told.
The child sex abuse royal commission heard on Wednesday Norman John Poulter, an officer at the Bayswater Boys' Home in Victoria, was charged in 2008 with 14 counts of child sex abuse against four boys.
A trial judge decided that a joint or group trial could be held, and coincidence evidence - in this case evidence showing children of about the same age complained about the same man in the same place - should be admitted.
When lawyers for Poulter appealed the judge's decision, the Victorian Court of Appeal ruled the evidence was not admissible and ordered separate trials.
Poulter was acquitted at two of those trials in April 2010 and the DPP then withdrew remaining charges.
Over the past two days the commission has been examining how tendency and coincidence evidence is used in child sex abuse criminal trials in different jurisdictions.
The decision on the admissibility of this type of evidence is made by judges.
On Wednesday, commission chair Justice Peter McClellan asked the Victorian Director of Public Prosecutions, John Champion SC, if he thought the question of the significance of evidence should be left to juries to decide.
Justice McClellan pointed out that most of the decision-making in a criminal trial is given to the jury.
Mr Champion said it would be a difficult balance to achieve a fair result in a trial if this happened, because a lot of the coincidence and tendency material could be highly prejudicial.
He did, however, say that, based on questions raised by the Royal Commission, he was concerned "we are losing trials we should not be losing".
He also said he thought the states should agree on an interpretation of the evidence rules.
Earlier on Wednesday, the commission heard a man raped when he was 12 years old by a pedophile Marist brother was asked during a trial if he had led on his abuser.
Peter Henry was assaulted by Francis William Cable at Marist Brothers' school in Pagewood in the 60s.
Cable, who was also known as Brother Romuald, was convicted in 2015 of 13 offences against Mr Henry and another complainant. He was sentenced to 16 years in prison with a non-parole period of eight years.
Mr Henry and other abuse survivors, who have given evidence at criminal trials, have told the commission that the stress of giving evidence is compounded when separate trials are held.