Well, the issue of the court I don't think is supportive because employer has right to hire and to fire any employee. So in the case of slashing your salary I don't think that should cause a problem it is either you leave the job if you have another thing to do or continue with the job because if you ask the business owner he/she will surely has reason for the slash of the salary. Even during this pandemic many companies really affected in order not to collapse, they are reducing their expenses.