So, the policy actually belongs to IRCC, not CBSA and I looked it up and read it again today since it had been a while. (Sorry, it's not publicly available/shareable.) And, I explained it wrong.
For 36(1)(c) to be applied, the act does have to be an offence against the laws of the country of origin and in Canada and cannot be the equivalent of a summary offence under their laws. So, bigamy is a good example. FGM would also be of the act was performed in a nation where it was prohibited by law, not just custom, and was equal in severity to an indictable offense there.