Levi Freeman-Quay, 26, faced the second day of his ACT Supreme Court trial on Tuesday, where he is defending an allegation stemming from a brawl outside the ActewAGL building in Civic in the early hours of September 21, 2013.

The Crown has alleged he was responsible for a punch that left victim Matt Pridham with a skull fracture, facial fractures, and brain damage.

On Tuesday, Freeman-Quay's lawyers were successful in having large swathes of expert evidence from a biomechanical engineer ruled out of the trial.

The expert, Dr Andrew Short, had analysed CCTV vision of the altercation and opined that Freeman-Quay was responsible for the punch that felled Mr Pridham.

But Chief Justice Helen Murrell ruled out much of his evidence, describing it as "rambling and full of generalisations", and ultimately finding his reasoning did not go beyond what a lay person could find using common sense.

Later on Tuesday, the court was shown a police record of interview with Freeman-Quay on the afternoon after the altercation.

Freeman-Quay told police he had begun drinking in the afternoon after finishing work, and then continued on in the city later that night.

He told police he remembered nothing of the fight.

The last memory he had, he told police, was of walking towards Mooseheads, a venue on London Circuit.

"Then that's all I can pretty much remember, getting handcuffed out the front of Mooseheads," he said.

Police later told the court of their efforts to track down some of the witnesses.

A number could not be reached or served with subpoenas, the court heard.

The judge-alone trial continues before Chief Justice Murrell on Wednesday.