Based on the scenario being describe it can be said that the main flaw in the supervisor's assumption is that people who sue for unjust dismissal usually claim the real reason for the dismissal differs from what the employer said. Mainly because the employers reasons are valid reasons for which the employer has the right to terminate the employees contract. Therefore employees usually say they were fired for another reason in order to have a better chance at winning the law suit.
The solution for this problems are found in the society due to the fact that the cause of the problem is usually in the society. Only the social approach can solve this problem since its nature is social, hence all the effort on this problem should be looked at from the social perspective :)
