If it has not been explained to you yet, it was because in a short PM to 3 persons (with the RM included) involved in a current conflict the past record of a certain poster and his//her flagrant and unapologetic violations was cited in regards to his/her current complaint. Whether PM messages are normally supposed to be dealt with and responded to like normal postings i know not.
The content of private messages must not be posted on-thread. The issues raised, however, may be raised anew on-thread for open discussion.