Stevedoring company DP World's decision to sack a worker for drinking alcohol on the job was inconsistent with its decision to give another employee, who was the son of a high-ranking Maritime Union of Australia official, a second chance.

A Fair Work Commission decision released on Monday found DP World was justified in sacking a Sydney worker with a previously unblemished record stretching 23 years but its decision to give the son of a union official a second chance demonstrated an "it's not what you know, but who you know" approach to its alcohol policy.

A stevedore who drank tins of Wild Turkey on the job was found to be fairly sacked. Credit:Glenn Hunt

The Fair Work Commission found that a stevedore was fairly sacked after he drank at least four tins of Wild Turkey bourbon in half an hour before he considered taking his own life at work on his birthday.

However, the Commission found DP World "have not implemented a fair and transparent system of enforcing" its drug and alcohol policy.