In August he received a letter, which detailed four separate incidents where he had been seen using his phone while operating a crane.
Mr Baines was told his phone was to be left in his car, or in the staff room, from then on.
"If it is found that during working hours when operating the crane you are using your phone, your employment will be terminated," the letter said.
"You are operating a large 60 ton crane that needs concentration and your full attention for simple safety reasons."
Later that month, a worker emailed Mr Smith, complaining about Mr Baines using his phone on the job.
He requested Mr Baines be replaced immediately.
Mr Smith then texted a copy of the email to Mr Baines and he was dismissed that day.
Authority member Helen Doyle said Mr Smith should not have accepted the word of other workers, without carrying out an investigation of his own.
"A fair and reasonable employer could have been expected to have carried out its own investigation."
She found that Mr Baines dismissal was not "procedurally or substantively justified" due to a lack of proper processes.
Mr Baines also should have been given notice that further use of his cell phone would put his employment in jeopardy, she said.
Such notice was important because at one worksite, Mr Baines was told to have his cell phone on him as means of communication, she said.
DSI was ordered to pay Mr Baines $5235.23 as reimbursement of lost wages and $4,800 in compensation for humiliation, loss of dignity and injury to feelings
However, because Mr Baines failed to leave his cell phone outside the crane following earlier warnings, remedies were reduced by 20 per cent.
