Justice Chisholm's 98-page report said an electronic search of Ms Collins' email, telephone and social media records turned up "very little" relevant material; her Facebook account had been deleted and comprehensive phone records were not available.
The report details how former Hanover director Mark Hotchin, who tasked public relations consultant Carrick Graham -- who then engaged bloggers Mr Slater and Cathy Odgers -- to "rebalance" the public perception of the businessman, whose company was being investigated by the SFO.
Justice Chisholm decided not to interview Mr Hotchin.
This week, Labour MP David Parker used parliamentary privilege to level fresh allegations against Mr Hotchin over an alleged smear campaign, and repeat calls for a police investigation.
Mr Feeley said yesterday: "You've got to ask yourself, even if he is available, were you going to get anything out of [an interview with Mr Hotchin]?
"Fundamentally, it was an inquiry into the minister's conduct and if he saw no connection between Hotchin and the minister then he probably decided there was no purpose in pursuing that; even if, as you say, there is any substance to what David Parker has said under Parliamentary privilege."
Mr Feeley -- who said his Queenstown job had not been affected by the Collins drama -- said he took comfort from the Chisholm report's observations that Ms Collins and subsequent Justice Minister Anne Tolley rated the SFO highly.
"I think most people see me as an unfortunate meat in a very unpleasant sandwich."
But he said it was concerning public servants could potentially be subject to a "pretty insidious" social media campaign with no effective way of countering it.
Should Ms Collins return as minister?
Mr Feeley said: "That's a matter for her, the prime minister and the political system, not me."