Patrick Clayton had asked the Alberta Court of Appeal to rescind his guilty pleas or, failing that, reduce his 11-year prison sentence.
Clayton, who was armed with a hunting rifle and 100 rounds of ammunition, herded nine people into a conference room in the downtown building in 2009. He surrendered peacefully 10 hours later.
He pleaded guilty to hostage-taking, pointing a firearm and possession of a weapon for a dangerous purpose.
Representing himself before the province's top court, Clayton argued that the trial judge had threatened him, that the Crown had promised a lighter sentence and that the hostage-taking was justified because of how the board treated him over a work-related knee injury.
The court, in a unanimous decision released Wednesday, said there was no evidence to support any of Clayton's claims and that the sentence was justified.
"His convictions are the result of his own actions – not the actions of the WCB," wrote the court.
"Many situations arise in life where individuals face disappointment because others do not meet their hopes and expectations. That cannot grant them license to commit violent acts and frighten innocent bystanders who then become the true victims."
Clayton, a self-confessed cocaine addict, had a long-standing beef over a claim for a knee injury he received on a construction site.
On Oct. 21, 2009, he stormed through the front doors of the compensation board building and shot over the head of a security guard. Clayton collected hostages as he rode up in an elevator and walked down hallways; others hid in their cubicles and crawled on their stomachs towards back exits.
Court heard Clayton herded the hostages into a conference room, then flung his gun around as he ranted about the compensation system and talked about it being "his last stand."
At first he ordered the hostages to tie themselves up. But he didn't care when they later got loose or went to the bathroom and never came back.
When he had one hostage left, Clayton gave the man a bullet as a souvenir, then surrendered to police. He became angry when he wasn't met by a TV reporter, as a police negotiator had promised.
The sentencing judge said Clayton showed genuine concern for the hostages but also caused them understandable fear.
He gave Clayton credit for the four years he spent in pretrial custody, and ruled he must serve half of the remaining six years and 10 months before applying for parole.
The Court of Appeal agreed it was a fit sentence.
"(Clayton) has not established that it should be altered in any way."
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