A Denver employee fired for drinking at work can’t be terminated, because the city failed to print out the results of a Breathalyzer test, a hearing officer recently ruled.

John Delgado works for the city as an equipment-operator specialist. In 2007, he failed a drug test required for all employees in safety-sensitive positions.

Rather than lose his job, he sought treatment and was required to abstain from drugs and alcohol for three years. He was fired after he failed an alcohol test last year.

The problem: The printer attached to the Breathalyzer machine malfunctioned and failed to print the results.

Even though Delgado didn’t dispute that he’d been drinking, the hearing officer decided he should keep his job because the city lacked hard proof. He was returned to his position and given back pay for the time he was out of work.

The city plans to appeal the ruling. In the meantime, the printer has been fixed and a backup system has been installed.

Lesson: This is an extreme case, but it underlines the need to buy robust printers, keeping them well maintained, and making sure there are alternatives if a key printer goes down.