In January Mr Retire was dismissed after a dispute with bosses who wanted to stop him from attending a mediation session with another union member, claiming Mr Retire had not given sufficient notice.
Mr Retire, the union delegate at the company, also acted as an interpreter for his colleague and said he felt it was his duty to help his fellow unionist.
After an investigation by the Employment Relations Authority (ERA), Mr Retire has won the right to return to work and compensation for the way he was treated by SPL.
The ERA ruled he should not have been issued the formal warning or sacked.
He will be paid 11 weeks of missed wages and $4500 compensation for "the humiliation, loss of dignity and injury to his feelings as a result of his dismissal by SPL".
The company would not comment today except to say they were still working to reinstate Mr Retire.
Mr Hargroves quit after the fake text debacle, but not before he accused Mr Retire of being aggressive.
A notice by management at the time said Mr Hargroves had "created many rumours and lies".
"He may have been using this incident to create problems," the notice said. "We understand [Mr Hargroves] has upset a lot of workers and we regret that this has happened.
"Some staff members chose to take matters into their own hands and solve the issue themselves without going to management first ... and have been issued with warnings for their actions."
Mr Retire was one of those staff members warned, a disciplinary action the ERA ruled was not appropriate.
ERA member Robin Arthur said there was no evidence that Mr Retire was aggressive towards Mr Hargroves.
Mr Arthur further went on to detail lies Mr Hargroves told SPL management who were investigating the claims, including that he was terrified during the conversation with Mr Retire when in fact he could be heard laughing in a recording of the incident.
"There was nothing inherently wrong with Mr Retire calmly approaching Mr Hargroves and attempting to establish whether there was any substance to the rumours about the text," Mr Arthur said in his decision.
"SPL's warning to Mr Retire was not proportionate or soundly based on evidence. Its action in issuing the warning to Mr Retire was unjustified."
SPL was also ordered to pay Mr Retire's legal fees of more than $3500.