Is social policing of unusual norm violations hard to learn?

Many social norms have the format ‘You shouldn’t do X. If you do X, people should punish you. If people don’t punish you, other people should punish them’. People mostly pick up the specific norms from observing one another and discussion about particular cases. That is, they learn what counts as X exactly and what punishment for variations of X is apt or required under what circumstances by whom. But learning in this way means they probably learn much more about the cases that come up and get tested, and less about norms that are almost never broken, or about behavior that breaks a common norm but in an unusual way. For instance, if someone lies, it is common to punish them by making their lying known to others, which they are expected to fear because others will distrust them. But if someone egregiously and obviously lies in public, that is in some sense more extreme yet also a more unusual case that people don’t have any practice with. The usual punishment of making their lying public isn’t available. Are observers required to make up a new punishment? Are other observers required to punish people who don’t make up a new punishment? A bit of uncertainty here quickly causes nothi