The Mounties were called to Vancouver airport after receiving reports that Robert Dziekanski had started acting strangely in the early hours of Oct. 14, 2007. (Paul Pritchard)

A forensic video analyst who told a public inquiry that Robert Dziekanski was acting aggressively toward Mounties before he was shocked by a Taser, conceded under repeated questioning Monday that his organization lists Taser International as a corporate sponsor.

Earlier, Grant Fredericks told the inquiry that his analysis of a witness' video of Dziekanski's death in October 2007, showed Dziekanski moving toward the officers shortly before he was jolted.

But Fredericks admitted on the stand that he has no training in photogrammetry and no more expertise in the science of making measurements by use of photographs than the average layperson.

Fredericks, a senior instructor with the Law Enforcement and Emergency Services Video Association, was questioned about his organization's affiliation with Taser and initially said there wasn't one.

"Let me suggest to you, sir, that one of the major sponsors of that laboratory and that program under LEVA is Taser International. Do you agree?" asked Don Rosenbloom, a lawyer for the Polish government.

"No, I don't think Taser even knows it exists and I've never had any involvement with Taser International," Fredericks replied.

Robert Dziekanski was stunned five times with a Taser by RCMP officers at the international arrivals area of Vancouver's airport. (CBC)

But as Rosenbloom pressed on, Fredericks' answers on the affiliation changed.

"I believe I saw Taser as one of the vendors at our conference last year," Fredericks said at one point, before being handed a document that listed Taser as one of the group's corporate sponsors.

"I think they've donated a couple of dollars to whoever sponsors the webpage. Reading anything more into that would be inaccurate," he said.

Fredericks, who graduated with a degree in broadcast communications from Gonzaga University and launched Forensic Video Solutions in the 1980s, said he himself never approached Taser for funding.

Kicking off the last week of testimony at the inquiry, lawyers for the four RCMP officers involved in Dziekanski's death might well have wanted to go out on a stronger note.

But Fredericks spent hours on the stand attempting to explain why his report was accurate, despite the fact it had been discredited in two other reports entered as exhibits by Rosenbloom.

Testimony questioned

Mark Hird-Rutter, a certified photogrammetrist who took the stand after Fredericks, said there were numerous flaws in the testimony of the RCMP witness. A photogrammetrist surveys and measures photographs.

"The first thing he's tried to do is he's tried to measure a length on Mr. Dziekanski's back and based on that length he's tried to suggest that Mr. Dziekanski has become smaller," Hird-Rutter said.

"The problem with this in terms of the size of Mr. Dziekanski is that we don't know if Mr. Dziekanski has actually shrunk down or if Mr. Dziekanski has actually become smaller. All we know is that it's been changed by three pixels."

Hird-Rutter added that it would be incorrect to say Dziekanski moved either forward or backward based on measurements he did of the scene.

The inquiry has heard from more than 80 witnesses, detailing every aspect of Dziekanski's time at the airport.

The public's focus has always been on the four RCMP officers who were called when Dziekanski started throwing furniture.

The Mounties have seen public support drop and have faced near-constant criticism since Dziekanski's death.

The force says it's learning from the incident, and is prepared to consider changes based on the inquiry's final report.

The final witnesses will testify this week, and closing arguments are set for next month.

After that, retired judge Thomas Braidwood will write his report, which could be ready by the fall.