As stated in the preface of The Battle of Red Mountain, the account of the Battle of Red Mountain was given to Malur Omayn after he confronted the god Vivec with Ashlander traditions about the battle, which are collected in the book Nerevar at Red Mountain, and with prophecies about the Nerevarine.
As a member of the Dissident Priests Malur Omayn would have been in danger of persecution anyway, as the group is outlawed and known members imprisoned. Malur Omayn must have known that confronting one of the gods of the Tribunal Temple, who is behind this persecution, with the Dissident Priest's accusations would cost him his freedom. It is known through conversations with citizens in Morrowind, that Malur Omayn was imprisoned within the Ministry of Truth.
- The Elder Scrolls III: Morrowind (Mentioned only)