My friend suffers from Bipolar Disorder. When he was on leave, he suffered mental health incapacity and unknowingly resigned from his position. The employer accepted the resignation in one day and asked my friend to come and sign the separation papers, which my friend complied to. While signing the papers my friend wrote some unwanted matters but employer disregarded that and my friend went home. When my friend realised his mistake, he unsuccessfully tried to get his job back. The employer said no. A medical certificate from a treating psychiatrist was submitted. The certificate said that my friend was suffering severe mental health incapacity and he did not have the capacity to resign from his job. The employer disregarded the medical certificate. My friend filed an adverse action application and Fair Work Australia arranged a conference and asked both the parties to negotiate the reinstatement. The employer tactically withdrew from negotiations and the adverse action application was closed.The employer then unilaterally sent a letter offering a six month salary as compensation with a threatening note that if the offer was refused then it would go further to court, then the employer will ask the judge to award all the costs. This action by the employer resulted in my friend spending one month in mental facility. However, the matter is not yet resolved. I am wondering how an employer can unilaterally offer a compensation to avoid reinstatement under Employment Law.