Nicole Proulx, head of the Senate's finance directorate at the time, testified at the suspended senator's fraud trial on Thursday that the "uniqueness" of the March 2009 expense claim prompted an employee to bring it to her attention.
It appears Proulx had no difficulty deciding whether the services of professional makeup artist Jacqueline A. Lambert — provided for a photographic shoot of Duffy's official Senate portrait — qualified for reimbursement.
"My reaction was no," Proulx said under questioning by Crown prosecutor Jason Neubauer. "It was personal."
Proulx, now the Senate's chief corporate services officer, said she then contacted Duffy's office to explain why it was not considered an appropriate expense.
Proulx recalled that she spoke with a member of Duffy's staff and asked "if she would pass on the information to Sen. Duffy so he would consider paying it himself."
"I was told no, that Sen. Duffy wanted to pursue this."
Proulx subsequently sent an April 9, 2009, letter to Duffy saying the Senate finance directorate is required to ensure claims and supporting documentation conform with rules and policies prior to reimbursement.
As a result, the directorate did not have the authority to process the invoice and returned the original material to Duffy.
The senator was advised he could ask the standing committee on internal economy, budgets and administration to consider the matter — something Duffy apparently took steps to do but ultimately opted against.
Duffy has pleaded not guilty to 31 charges of fraud, breach of trust and bribery concerning his Senate expense claims.
The minutiae of the contractual paperwork Duffy filed during his initial years in the upper chamber continued to hold the spotlight at the trial Thursday.
Neubauer walked Proulx through the details of a series of Duffy's contracts for editorial services.
Some of the criminal charges Duffy faces involve $65,000 in contracts awarded to friend Gerald Donohue.
Some of that money later wound up in the hands of others through Donohue's companies.
Previous testimony at the trial indicates Lambert was among those paid with these funds — in her case to do Duffy's makeup before a television appearance with Prime Minister Stephen Harper.
The defence has argued that while there might have been some administrative errors, Duffy's contracts with Donohue involved legitimate Senate expenses.
Follow @JimBronskill on Twitter
Also on HuffPost