[flerdle] Isn't it the same in some parts of the US? There was an early "King of the Hill" episode where Hank's company had trouble firing an employee for drug use because of a similar law. In the end, Hank resigned and then they were able to fire the addict because they had few enough employees to be exempt from the law.
I have no idea what the USA does, but our PM is the ... nevermind.
Another trick is to make all your employees "contractors", or keep them as a succession of short-term casuals. Then they don't count towards your total, and they aren't covered by the unfair dismissal laws anyway.