Warwick Parer, and others, have been referring to a supposed convention that a spill motion must be accepted as carried by the chair of a parliamentary party meeting when the vote is in fact even. While this seems unlikely, it has been uncritically accepted by a number of commentators.
David Fraser is an expert on the Queensland Liberal Party, redistributions, and the party’s history. He writes:

I was reviewing some historical material last night asnd came across a reference to the change of Liberal leadership in 1978 when Llew Edwards replaced Bill Knox. In view of the events of the past ten days, and references to “conventions”, it’s rather interesting.
On 20 September 1978, at a parliamentary party meeting, a motion to suspend standing orders to allow for the moving of a motion declaring the leadership vacant was lost after an 11-11 tie (with one abstention).
Two weeks later another meeting was held and the following motion was moved and carried: That the leadership be declared vacant (Moved: Terry Gygar; Seconded: Bruce Bishop).
So much for the notion that the Liberal Party has a convention that leadership challenges must result in the automatic declaration of a vacancy.
By the way, the motion was carried 13 to 9 and Llew Edwards was the sole nominee for leader.
Ayes: Rob Akers, Brian Austin, Bruce Bishop, Tony Bourke, Llew Edwards, Terry Gygar, Bill Hewitt, Rosemary Kyburz, Don Lane, Col Miller, Guelph Scassola, Norm Scott-Young, Terry White
Noes: Fred Campbell, John Greenwood, Bill Kaus, Bill Knox, Norm Lee, Bill Lickiss, John Lockwood, Bob Moore, Charles Porter
Sam Doumany abstained and there was a vacancy in Sherwood following the death of John Herbert.

Let’s be charitable and say Parer is ignorant of the processes of the party. He wouldn’t just be asserting something because it supports his aims, would he?