However, Captain Howieson was found guilty of charge three.
He appealed the conviction in Brisbane, claiming the original proceedings should have been declared a mistrial when the Chief Judge Advocate ordered he be acquitted of charge four.
On Friday, three judges from the Defence Force Discipline Appeal Tribunal, based in Brisbane’s Commonwealth Law Courts, delivered their judgement and agreed with Captain Howieson.
Justice John Logan, Justice Paul Le Gay Brereton and Justice Melissa Perry ordered his appeal be allowed, his original conviction be quashed and he be given a new trial on charge three.
“On the appeal, evidence was led, without objection, from Captain Howieson, that he was neither advised about the prospect of making an application for a mistrial, nor were instructions sought from him with respect to the making of such an application,” the justices concluded.
“At trial, following the directed acquittal in respect of charge four and related direction about the ignoring of related evidence, all that occurred was that Captain Howieson simply continued his evidence in chief.
“The panel was exposed to highly prejudicial material, which had a tendency to induce a subconscious bias against Captain Howieson.
“It follows that there has been a substantial miscarriage of justice.”