Contradictions from Monks regarding Precepts vs Commandments and punishment

Now this is often raised whenever a monk teaches and talks about the five precepts. They often say that these are not, like in the judeo christian faith, commandments and that no higher entity or something will punish one. Now to my question: These monks belief in post mortem rebirth (I do not) and they therefore employ wrong speech regarding the aspect of punishment. One is getting punished (hell realm etc.) if one is not in line with the precepts (based on their view on post mortem rebirth). Can anyone explain this phenomena?