Lisa Bird and Rachael Roberts were both employees at Tasmanian real estate agency The View.
According to legal documents, the employees’ initial dispute was over who was to blame for a lost sale.
Following the disagreement, Bird stopped greeting Roberts in the morning and removed her as a friend on Facebook.
Commissioner Nicole Wells ruled that Bird had behaved unreasonably, and showed a “lack of emotional maturity”.
Roberts had allegedly complained to her boss, James Bird – the husband of Lisa Bird – that her properties were not being fairly represented in the agency’s window.
In response, Mrs Bird called a meeting with Roberts, where she was said to have accused her co-workers of being a “naughty little schoolgirl running to the teacher”.
After the meeting – which Roberts left visibly upset – Roberts logged into Facebook to check whether Bird had made any comments on the social media platform about the circumstances.
It was then that Roberts discovered Bird had deleted her as a friend.
“Mrs Bird took the first opportunity to draw a line under the relationship with Ms Roberts,” Wells ruled.
“She removed her as a friend on Facebook as she did not like Ms Roberts and would prefer not to have to deal with her.”
Wells found that this was evidence of “a lack of emotional maturity and is indicative of unreasonable behaviour”.
She added that Bird’s reference to Roberts as a “schoolgirl” was “provocative and disobliging”.
Following the incident, Roberts was diagnosed with depression and anxiety, and deemed medically unfit to return to work until the dispute had been resolved.
Last week, the Fair Work Commission (FWC) ruled that ‘unfriending’ a colleague on Facebook amounted to workplace bullying.