Good news to report here:
Holy Damage Resistance PvP/PvEhttps://report.nostalrius.org/plugins/tracker/?aid=3660Shahkar (shahkar)25 minutes ago
Status changed from Invalid to Reopened
Shahkar (shahkar)25 minutes ago
http://imgur.com/ZSvdhiW - Confirmation that players have "invisible" holy resist.
http://wowwiki.wikia.com/wiki/Resistance - "There was no resistance stat for Holy, and as such no players nor NPCs could resist Holy spells."
Two things are implicated here - Firstly, that there is an invisible stat for holy resist contained within the "all resist" stat. Secondly, that there WERE partial or full resists in PvE, but only due to the level difference between the player and the target. Therefore, somehow there is Holy Resistance (this is a common issue on MangoS private servers, I've seen it time and time again) that needs to be removed.