A week later, Ms Guise was was involved in a verbal altercation with a colleague. Mr Black said he was concerned about that, as he had told staff not to have internal arguments in front of CPIT students or staff.
In December 2012, Ms Guise received a phone call 90 minutes before she was due to start work, and was told by Mr Black she had been removed from CPIT because of "client frustration", the authority said.
She said she asked for an explanation but was not given one. When she asked for work at another Allied site, she was told nothing was available, the authority said.
Ms Guise said she was told she would be stood down for two weeks and then re-employed on a casual basis.
When she raised money issues, Ms Guise said she was told she could not have her holiday pay or days in lieu paid out.
Mr Guise said she resigned because she felt like she had no choice, as she needed the money before Christmas, the authority said.
Allied's lawyer, Chris McDowall, said Ms Guise was instructed by Mr Black that if she wanted her two week notice period waived, she would have to get it signed off by another manager.
On Mr McDowall's advice, Mr Black asked Ms Guise to reconsider her resignation, but she once again confirmed it, the authority said.
Ms Guise claimed she was constructively dismissed. However, Allied disagreed and claimed Ms Guise's termination was mutual and occurred in accordance with a clause in her individual employment agreement.
Authority member Michael Loftus found Ms Guise was not only constructively dismissed, but she had a personal grievance, as she was unjustifiably dismissed.
"The evidence shows Allied simply bowed to pressure from CPIT and acted without first conducting its own inquiry or investigation.
"Furthermore the lack of inquiry means I have no evidence of wrongdoing on Ms Guise's part or, at least, wrongdoing that may have warranted dismissal."
Mr Loftus ordered Allied Security to pay Ms Guise $4911 for lost wages as a result of the dismissal, $4000 in compensation for humiliation, loss of dignity and injury to feelings, and $594 for outstanding payment in lieu of public holidays.
Costs were reserved.
Ms Guise said she was very pleased with the outcome and did not wish to make any further comment.
An Allied Security spokesman said it would be appealing against the decision at the Employment Court.