That assumes that the government employees are independent of one another and will not "punish" the person reporting the incident.

What works better is a system where the PM alone is allowed to take bribes with impunity but no one else is allowed to. The reasoning behind this is it gives the PM and his inner circle sufficient financial independence to implement anti-corruption measures.

For example, the central government in China has been known to mete out capital punishments on mid-ranking politicians found to take bribes. This limits the base of people who are able to seek an economic rent on the basis of their position. Like any triangle, the people at the top may get filthy rich and in many sense untouchable; they will be able to keep the large pool of people below them honest.