Four RCMP officers used reasonable force when they confronted Robert Dziekanski at Vancouver's airport and stunned him several times with a Taser, a police expert said Thursday at a public inquiry into the man's death.

Sgt. Brad Fawcett of the Vancouver Police Department said because the officers believed Dziekanski was about to attack them or someone else with a stapler, they had reasonable grounds to use the Taser.

Yet Fawcett, who provided a report to homicide investigators on the use of force against Dziekanski, said he probably would not have reacted the same way in the same situation.

Fawcett said his evaluation hinged on what the officers perceived at the time -- regardless of whether those perceptions were actually correct.

"What matters in terms of the use-of-force analysis is: What was the officer's perception of the resistance?" said Fawcett.

His report elaborated further: "The reasonableness of a particular use of force must be judged from the perspective of a reasonable peace officer on the scene, rather than with 20/20 vision of hindsight."

Police were called after Dziekanski started throwing furniture in the early hours of Oct. 14, 2007. They stunned him within seconds of arriving, and he died shortly after.

The Taser was deployed five times, although RCMP say its unclear how many times the device made contact with Dziekanski.

Fawcett had viewed a witness video of the fatal confrontation, but much of his report reflects statements the officers gave to investigators.

The inquiry has heard that those statements conflict with the video, but Fawcett found the officers' statements were supported by the video.

For example, his report appears to accept the officers' claims that Dziekanski remained standing immediately following the first Taser jolt, with his hands clenched around the stapler. The video shows Dziekanski flail about for a few seconds before collapsing on the ground.

When one of Dziekanski's arm lifts above his head, the stapler visibly flying away, Fawcett's report describes the action as "consistent with striking or throwing."

The report brushes aside other inaccuracies -- for example, that Dziekanski had to be wrestled to the ground -- as "minor in nature."

Fawcett agreed with the officers that Dziekanski appeared to be fighting back after he collapsed to the floor.

He said it doesn't matter whether Dziekanski was actually resisting or if he was reacting to the pain of the Taser.

"If the officer perceived it to be a response to the push-stun (Taser deployment), that would be one thing," he testified.

"If the officer's perception was it was conscious resistance on the part of the subject, then that's another matter."

Still, Fawcett said he doesn't think he would have reacted the way the officers did.

"In any group of officers, you'd have a range of responses -- would I have done the same thing? Probably not," said Fawcett, who wasn't asked to elaborate.

The lawyer for Dziekanski's mother said police officers aren't off the hook just because they perceived something. The perception must be reasonable, he said.

"So it's not just what he perceives. What he perceives has to be reasonable, correct? It's measured against what is a reasonable perspective, right?" asked Walter Kosteckyj, himself a former RCMP officer.

"Yes," replied Fawcett.

Outside the inquiry, Kosteckyj said the officers' actions didn't meet that test.

"Given the number of officers involved, given the kit that they were outfitted with, given who they were dealing with -- what would a reasonable officer do in that circumstance?" said Kosteckyj.

"A reasonable officer should have handled that in a different way."

Kosteckyj said the report raises fresh questions about the decision not to charge the four officers because Crown prosecutors had access to the report when they ruled out charges.

"It seems the Crown should be commissioning a separate report," said Kosteckyj.