A "crowd controller" at one of Darwin's most popular nightclubs has faced the first day of a Supreme Court trial, accused of striking a US Marine who "could have died".
Hayden Summers pleaded not guilty to one charge of unlawfully causing serious harm to the visiting Marine in April 2021.
Crown prosecutor Ian Rowbottom, in his opening address, told the jury their case would be that US Marine Glen Thomason had been drinking with friends on Darwin's party strip before he was ejected from Monsoons nightclub in the early hours of April 11, 2021.
CCTV of the Marine's interaction with Mr Summers at the side door of the club in Darwin's CBD was played to the jury, showing what prosecutors described as a "heated" exchange, before Mr Thomason was struck to the side of the face and fell to the ground.
"It's agreed between the parties, in essence, Glen Thomason's injuries from that evening resulted in him spending a significant amount of time in hospital," Mr Rowbottom said.
"If it were not for the medical intervention of the doctors, he would have died."
The court heard Mr Thomason had a part of his skull removed and required significant rehabilitation.
"[Mr Thomason] fell over, we say, as a result of Mr Summers," Mr Rowbottom said.
"We've all heard 'one punch can kill' and in relation to that, this is a case essentially about one punch… or a blow."
Mr Rowbottom told jurors they would hear from several US Marines throughout the trial, including the alleged victim himself.
"You'll see [Mr Thomason], for the first time, watch the CCTV," he said.
Hayden Summers' barrister, Peter Maley, told jurors the "fundamental issue" of the case would be whether prosecutors could prove the bouncer was not acting in self-defence.
"Look carefully at what you see on the video… look at the conduct of the parties, the bodily movement," Mr Maley said.
"The crown have to prove beyond reasonable doubt the defendant was not acting in self-defence."
'I could kill you': First witness gives evidence
Security consultant Michael Siebert told the jury he stood across the road from the nightclub's exit when the alleged incident occurred and could hear Mr Thomason "screaming".
"He said 'I could kill you'," Mr Siebert told the court.
The witness, who told the jury he fought martial arts for many years, described Mr Thomason's manner as "aggressive", but said he did not attempt to assist Mr Summers in the situation.
"[Hayden Summers] was doing their job… they're licensed security guards," Mr Siebert said.
CCTV of the alleged incident was played to the jury, but not released to the media, from multiple angles and at times slowed down.
According to prosecutors, Mr Thomason could be seen making a "rapid arm movement" in the moments before he was struck.
Mr Siebert told jurors the movement was "100 per cent" an attempt to "take a swing" at the accused.
When Mr Rowbottom asked the witness why he refused to give a statement to police about the alleged incident, he told the court it was his "right" and that he would "wait until the court date".
Under cross-examination, Mr Siebert said Mr Summers "wasn't being aggressive at all" however agreed he did see the accused slap Mr Thomason across the side of the face.
The trial continues.
