Brian Dietrich denied he made the arrangements for the officers to meet at the perjury trial of former RCMP Corporal Monty Robinson.
Robinson is charged with lying eight separate times at the Braidwood Inquiry in 2009. Robinson testified at the inquiry that he had not spoken to the other officers involved in Dziekanski's death before appearing at the inquiry.
A key part of the special prosecutor's case relies on the evidence of Dietrich's ex-spouse, Janice Norgard. She said that on a weekend morning just before the first officer testified in February 2009, all four Mounties sat around the kitchen table in her home in Richmond.
Norgard says the gathering was coordinated by Dietrich, who is the cousin of one of the accused - RCMP Constable Bill Bentley.
However, Norgard has linked her recollection of the event to a time when she says Dietrich was no longer living in the house.
On Tuesday when shown a raft of phone records suggesting she could be mistaken, Norgard repeatedly rejected the evidence.
"I don't recall making specific calls from 2009." Norgard said when questioned about how the calls could be explained.
When Robinson's lawyer David Crossin asked Norgard to comment on a bill from the couple's Internet service provider that also raised doubts about her memory, Norgard called the evidence "completely irrelevant."
Crossin also introduced details from Norgard's own cell phone records indicating she wasn't even at home on key weekend dates when she says witnessed the meeting.
A number of times in her testimony, Norgard has disparaged her ex-husband. On Tuesday she called him "a proven pathological liar."
Dietrich, a 52-year-old pilot for Air Canada, testified his ex-wife is mistaken about events that occurred more than five years ago.
"During this time frame," Crossin asked Dietrich, "was there a meeting at the house between Bentley and the three other RCMP officers?"
"No, there hasn't been a meeting between these officers, in that time frame," Dietrich said.
The issue has taken up weeks of court time because it is important to the Crown's overall case.
A member of the team of prosecutors went so far as to say that proving the officers lied about meeting before testifying at the Braidwood Inquiry would make it more likely for a judge to conclude the officers lied about other details.
It's unclear how the Crown now views the value of an allegation for which significant doubt has been raised.
The special prosecutor is expected to cross-examine Dietrich when court resumes today.