But forensic pathologist Professor Johan Duflou could not pin down exactly how Jae-Ho Oh died, instead pointing to a number of possible fatal consequences of his injuries.

They included extreme blood loss, air in both chest cavities, air in a blood vessel that ended up in his brain or a possible injury to his spinal cord.

Mr Oh's friend Joshua Higgins is on trial in the ACT Supreme Court accused of murdering the 56-year-old in the early hours of March 11, 2019 after a heavy drinking session.

The 32-year-old has pleaded not guilty to murder, but he admits he stabbed Mr Oh in his Gungahlin townhouse.

READ MORE: Man accused of stabbing drinking buddy 14 times

Professor Duflou told the jury on Monday that Mr Oh had fatty liver and heart disease, but while poor health from alcohol abuse may have contributed in some way it was not the main cause of death.

"A person with an entirely healthy heart may have been able to cope with injuries better," he told the jury.

He said if the stab wound to the neck had damaged the spinal cord it might have been fatal "similar to a decapitation injury".

The jury was also shown graphic photos from the autopsy.

Professor Duflou said other than injuries to his chest and back, there were bite marks on Mr Oh's right arm and a "relatively minor" fractured skull.

The alleged murder victim had a number of marks on his hands and arms, the court heard.

Professor Duflou said those types of marks "you worry about them being defensive injuries".

The trial continues.