Gay hate case 'not a game', NSW ex-homicide cop says

A former top NSW police officer has denied at a gay hate crimes inquiry he viewed the unsolved death of an American mathematician as "a game" against the man's family.  

Ex-deputy commissioner Michael Willing is being quizzed at the inquiry about the 1988 death of US man Scott Johnson, whose case was initially ruled a suicide before it was reopened in 2012 following pressure from his family.

A coroner in 2017 determined the matter involved human intervention and in February Scott White pleaded guilty to Mr Johnson's manslaughter in the NSW Supreme Court.

Mr Willing was asked on Monday about the view of investigating police, including ex-detective Pamela Young, who formed the view Mr Johnson's death was likely suicide.

Mr Willing said he "ultimately" was not able to determine if Mr Johnson's death was homicide, suicide or misadventure, saying his view on the case changed over time.

"I thought there was no evidence to indicate it was a homicide," he said.

He denied sharing Ms Young's view that Mr Johnson's family was wrong to keep "pushing" the homicide theory.

He also rejected the proposition he considered the family to be police opponents but conceded the relationship between police and the family became "adversarial".

"I didn't consider defeating them (the Johnson family) to be an objective," he said.

Taken to a text message exchange with Ms Young in which he wrote "we will work through and come out on top", Mr Willing said he was "attempting to appease" his colleague.

"She was extremely upset I didn't see it as a game with a winner or loser."

Asked about Ms Young's interview on ABC TV Lateline's program in 2015, when she told the program Mr Johnson likely died by suicide, Mr Willing said approval for it may have been possible, but that more police sign-offs would have been needed.

He agreed, after being taken to notes related to the "explosive" interview, it was "crystal clear" Ms Young thought the death was due to suicide and would not be solved.

"That was in fact her view," counsel assisting the inquiry Peter Gray SC said.

"Yes," Mr Willing replied.

The former homicide squad boss previously fronted the inquiry in February, when he was questioned about Strike Force Neiwand's probe of more than 50 suspects involved in the murders of three gay men in the 1980s.

The inquiry is probing unsolved suspected hate crime deaths of LGBTIQ people in NSW between 1970 and 2010.

It continues before Commissioner John Sackar.