First of all, you have to look at the source of the information. The blog where this story links to is full of such gems of articles as: "The Earth is NOT Moving!! There is NO proof that the Earth rotates on an "axis" daily and orbits the sun annually. None."

I remember the Port Arthur massacre well, I wasn't there, but plenty of people were. There were witnesses who saw Martin Bryant on his massacre - aside from the people who saw him that weren't shot, there were 15 survivors of his rampage that left 35 people dead. He set up a video camera to record his violence in the Broad Arrow cafe, so any cover up would have had to have involved police officers at every level, all of the witnesses and the politicians who supposedly wanted to change gun laws so badly that they would kill 35 people to do it.

My reaction was that if he was not to get a trial by jury then, being an intellectually challenged and deranged person, he would have to be judged and sentenced according to his mental condition. Well, how about temporary insanity then? No, the Australian people had been worked into such a frenzy by the press that nothing less than the maximum penalty would be tolerated for Martin Bryant regardless of his condition. God only knows where those snivel libertarians were in this instance. Isn't everyone entitled to a fair trial? And is not everyone innocent until found guilty? Apparently not in this case.
http://www.historicaltravelguide.com/port-arthur-in-tasmania.html

1. Australians reacted with horror and outrage when, on the evening of Sunday 28 April 1996, they learned that over 30 people had been murdered and many others injured in an orgy of violence at the Port Arthur Historic Site (PAHS), Tasmania, one of the nation's most venerable historic sites, and at adjacent locations.

The alleged perpetrator—a young Caucasian male with long blond hair, named Martin Bryant—was apprehended by police the following morning after he emerged from a burning tourist guest house, Seascape Cottage, which was located a short distance from Port Arthur.

Bryant instantly became the most vilified individual in Australian history and was rapidly enlisted in the serial killers' hall of infamy as the world's second-most-lethal gunman. However, the case—which never went to trial—is full of clues, direct and indirect, to suggest that Bryant, a 29-year-old man with an IQ of only 66, was framed.

However, even today, the case is regarded by most people as so delicate that it is considered insensitive to discuss it at all—a perfect means of perpetuating a cover-up, if ever there was one.

Martin Bryant's guilt: the problem of lack of evidence
Strikingly absent from the recent media coverage of the 10th anniversary of the most traumatic event in modern Australian history was evidence to support the official claim that Martin Bryant had been responsible for the massacre.

The matter of whether Bryant had really been the perpetrator was only touched upon in an interview with Bryant's mother, Carleen Bryant, that was published in the Bulletin of 4 April 2006:

"She likes to talk about her boy's hair. It's another reason she thinks he has been framed. 'He had beautiful, shampooed soft hair.' Carleen wants to set the record straight. 'The guy who did it had dark, greasy hair and pocked skin. My Martin has lovely soft baby skin.'"

The writer of the report, Julie-Anne Davies, of course does not raise the subject of whether Carleen Bryant has any evidence to support her claims, simply observing patronisingly that Mrs Bryant "lives in a state of denial". As I will show in this report, however, it is Julie-Anne Davies who is living in a state of denial—as are all Australians who think that Martin Bryant was responsible for the tragedy. There is simply no hard evidence to support this belief.

Most Australians, when confronted by the heretical idea that Bryant might not have been the gunman, respond in knee-jerk fashion: "Of course he was! People saw him do it!" In fact, it has never been proven that Bryant was the man "people" saw do it. It was the police and the media, not the eyewitnesses, who identified Bryant as the gunman.
As we shall see, only two eyewitnesses have ever specifically identified Bryant as the perpetrator, and both of them gave their statements a month later—after they had been influenced by the publicity given to Bryant in the media.

If you ignore the media propaganda and study the details of the case, what becomes readily apparent is that there is no evidence that Martin Bryant—alone and to the exclusion of all other young men with long blond hair—executed the massacre. What's more, there are compelling reasons to believe that Bryant could not have done it. As Carleen Bryant told the Bulletin, "He didn't have the brains". Above all, he didn't possess the shooting ability.