He left tools that were too big or that were fixed in the workshop, filing a list of items he owned but which remained at Fabri-Cell.
Fabri-Cell is believed to deal with medical, industrial and safety equipment.
"Mr Eason made no attempt to hide what he was doing as he loaded his tools into his car in front of other employees who knew he was leaving work early that day," the authority said.
A few days later, one of the company managers, Dianne Ferguson, who had two other employees with her, called Eason into her office.
"Mrs Ferguson handed Mr Eason a dismissal letter which had been signed by her. Mr Eason says he was shocked at his dismissal and didn't understand why he
was being dismissed when he had already resigned.
"Mr Eason also says he was surprised that it was Mrs Ferguson, in the presence of two other employees who acted as her witnesses, because Mrs Ferguson had never been his manager."
Ferguson said Eason's usual manager, company chief executive James Deo, had given her the letter to give to Eason.
The letter said he was being sacked because he told colleagues he was resigning before handing in his written notice; failing to advise of his whereabouts on July 28 and 29, although he had told another colleague he was off sick; submitting annual leave forms for those absences; and removing company property Fabri-Cell argued it owned.
"I find that all of these reasons for dismissing him are without merit. Mr Eason
gave the correct contractual written notice," said ERA member Rachel Larmer.
Eason provided proof of ownership of the tools, including insurance documents for the tools that were stolen in 2009, as well as receipts for the new tools.
"Mr Eason viewed the allegation about taking company property very seriously.
He says he saw that as an allegation of theft against him, which highly distressed him.
Larmer rejected Fabri-Cell's assertion that it had bought the business as a going concern so owned all tools used on the premises.
Ferguson acknowledged that the new owners did not communicate that view to staff so Eason had no opportunity to show the new owners the tools he owned.
"Fabri-Cell's lack of evidence was contrasted with Mr Eason's detailed evidence
of ownership, which was supported by receipts, photos and other documentation," the ERA said.
It found that Eason's sacking was procedurally and substantively unjustified, and that the issues Fabri-Cell raised did not justify dismissal.
The ERA ordered Fabri-Cell to pay Eason $9000 for distress, $3081 holiday pay, $1560 lost remuneration, $1286 legal costs, $483 in wage arrears and a $72 filing fee.