Gittin 54 - Penalizing for transgressions

If one mistakenly violates a Rabbinical prohibition, should he be penalized? Rabbi Meir says, "Yes, because people in general take Rabbinical decrees lightly, and therefore they should be upheld all the more." Rabbi Yehudah says, "No, Rabbinical prohibitions carry less weight than those of the Torah, therefore additional penalties are not justified."

If a priest is bringing someone's sacrifices and at the same time is planning to finish the service after allowed time, the sacrifice is invalid. If he did so on purpose, he has to pay the owner for the ruined sacrifice.