He then unwrapped the cake and took a bite of it, offering it to other staff members who laughed.
Later that week he was called to a meeting to face allegations of taking and consuming products without authorisation.
The owner of the supermarket, Kyle Burnett, told the authority that at the meeting he questioned Mr Mutze about previous instances of him marking down products, taking home a broken office chair and asking to use the carpet cleaner for an extra day because he had wanted to see whether eating the cake from the waste bin had been evidence of a pattern of behaviour of wanting free or cheap goods.
The authority also heard the supermarket had a policy that unauthorised possession of company property including scrap, waste and damaged items was cause for instant dismissal.
Mr Mutze told the authority he wanted to continue working in the supermarket industry and wanted to avoid having the dismissal on his employment record.
Notes from the meeting recorded Mr Mutze as saying "I want to avoid it to go on my record. Willing to make a deal with Kyle. Deal it won't go further and I will resign.''
He later tended his resignation.
The authority found Mr Mutze was not unjustifiably dismissed, but found he suffered an unjustifiable disadvantage during a period of suspension, for which he was awarded $500.