He drove his truck, with Bunnings livery, across the road with his partner Melissa Donoghue in the cab holding the unrestrained baby girl on her lap, according to the ERA finding.
A member of the public saw them and called police, who telephoned a manager at Bunnings Paeroa, who then contacted Kings.
Two days later, when Mr Cochrane went to Bunnings Cambridge to pick up an order of damaged decking timber, he ended up in a row with the trade supervisor. The man had sold the damaged timber on, without informing Kings, who had arranged with Bunnings to pay for the order which had been damaged in transit.
The argument "became heated", the ERA said, with the supervisor claiming in an email to Kings that Mr Cochrane had called him "an idiot", and asked if he was having a period. Mr Cochrane later admitted asking the man: "Are you on the rags?"
Mr Cochrane said the supervisor had "spat the dummy" after he told him it was "illegal" to re-sell the timber for which Kings had paid credit.
He was called to a disciplinary meeting on March 4, and was later sacked for serious misconduct.
However, the ERA said Kings had failed in its duty to follow proper procedure in the dismissal process, including an inadequate investigation and unfair weighing of the facts, not exploring alternative disciplinary options, and not telling him that dismissal was a potential outcome of the disciplinary meeting. It also said the outcome was pre-determined, with some of the managers involved not hearing directly from Mr Cochrane, and that the evidence did not support a finding of serious misconduct.
It ordered Kings to pay Mr Cochrane $7956 as lost wages, and $5100 in compensation.