Mr Gillman-Harris had befriended the teens and took them to the motel, where he'd allegedly offered to pay for sex. The defence claimed the teens acted in self-defence and Mr Gillman-Harris had sexually assaulted Nattrass-Berquist when Wallace-Loretz was in the bathroom. Wallace-Loretz had then come to his friend's rescue as they fought Mr Gillman-Harris off, it was claimed, leaving the older man with skull factures.
However, text messages between the teens before they checked into the hotel showed they had discussed robbing and assaulting Mr Gillman-Harris.
Nattrass-Berquist said he was going to "f*** a gay c*** up".
It is no longer possible for people to argue they should be convicted of manslaughter rather than murder because they were provoked. That change came after Clayton Weatherston, who murdered his ex-girlfriend Sophie Elliott, used the defence in 2009.
But it had been employed successfully and even dubbed the "gay panic defence" in two high-profile cases. In 2004, Phillip Layton Edwards was found guilty of manslaughter but acquitted of the murder of celebrity interior designer David McNee.
Edwards argued Mr McNee had touched him in violation of an agreement between the pair when Mr McNee paid for Edwards to perform a sex act.
Ferdinand Ambach, in 2009, was successful in arguing provocation during his trial over the killing of Auckland man Ronald James Brown, who was found with a banjo shoved down his throat.
Ambach claimed Mr Brown, who was gay, made unwelcome sexual advances.
Auckland University associate law professor Bill Hodge said, while the teens in this month's trial were finding it hard to argue provocation, they were appealing to the jury to consider it.
Sometimes the actions of a victim could also be relevant in juries deciding whether it is murder or manslaughter, often a "compromise" verdict.
"But defence lawyers will still throw self-defence, they'll throw provocation, they'll throw other forms of justification," Dr Hodge said.
"Lawyers will continue to throw everything they can and that's their duty."
Otago University law professor Mark Henaghan said Wallace-Loretz and Nattrass-Berquist were arguing for an acquittal based on self-defence. Provocation could be taken into account by the judge at sentencing, he said.