Ms Metcalfe called a meeting with Mr and Mrs Gane to discuss what she believed to be Mr Gane's unacceptable behaviour towards his wife, for which he apologised, the ruling said.
But Ms Metcalfe told the authority the highest cause of stress resulted from an accounting system introduced to keep track of money on the premises.
The system was met with resistance from Mrs Gane and created friction between the two women.
Ms Metcalfe said no action was taken by management to lessen the problem.
Three months after Ms Metcalfe began working for the company, she attended a four and a half hour performance review.
A few weeks later, with little warning, Ms Metcalfe was called to a continuation of the performance review, during which she started to feel unwell.
She was diagnosed with workplace stress.
Ms Metcalfe took unpaid sick leave from the end of October 2013 until her resignation on December 13, 2013.
She told the authority that she was disadvantaged in being unpaid during her time off sick, but authority member Eleanor Robinson said it was not an unjustifiable action by the company.
However, she said the office environment contributed towards Ms Metcalfe's stress and no formal steps had been made by the company management to address her concerns.
She awarded Ms Metcalfe $10,000 compensation for "significant hurt and distress" and three months lost wages to be calculated by the parties involved.
Mr Gane said he did not want to comment on the ruling.
Ms Metcalfe could not be reached for comment.