Can you help me identify who can sue whom , and who can be successful in his/her claim(s). Also, state defence(s) that may rise by a party. Also parties's contractual rights and obligations.

Scenario 3: Ms Thi NgocHien Vo was employed by Hung Vien Tran as a casual employee at a shop in Cabramatta, called Thu Phung Desserts. Ms Vo had fixed rostered working days on which she worked limited fixed hours as a casual employee. At approximately 5 pm on 13 October 2018, Ms Vo attended the shop to purchase a drink and to meet her friend who was working there at the time. Ms Vo was not rostered to work on this day. On anival, another employee, Ms Hoa asked Ms Vo if she would help to clean the floor. A tiled area of the floor was wet because Ms Hoa just dropped a water bucket but she was too busy to clean it up. Ms Vo slipped on the wet floor, coming into contact with the sugar cane juicing machine that was operating. Ben was the staffresponsible for operating the machine but at the time of the accident he left it unattended briefly for about two minutes to go to the restroom. Ms Vo's left hand was cmshed into the machine, causing significant injuries. At the date of the accident, no request had been made by or on behalf of the owners for Ms Vo to work for them on the day of her injmy and the evidence suggested that they were completely unaware of her presence on their premises on that day