The men were initially at the Robertson high-rise on Kennishead Avenue with others before Mr Doris left.

Roberston came out after him. There have been allegations that Mr Doris assaulted Robertson.

The killer was later described by a witness as being “absolutely enraged”.

He returned to his apartment, stormed out and performed a “full force pushing motion” with his arm towards the victim’s chest.

Mr. Doris begged a friend to get him an ambulance. By the time they got off, he was slumped on the elevator floor.

In his testimony, Robertson denied being angry that day. He also said he did not know how Mr Doris had been injured and only remembered seeing him “rolling on the ground”.

Prosecutor Mr MacIntosh, in his closing address to the jury, said Robertson’s testimony “made no sense” and was “fabricated” to help him.

Victoria Young, defending, said during sentencing that her client maintained his position during the trial.