While repairing walls in Chalman Keep, I noticed the following:
(1) There was a random load screen: All walls subsequently appeared to be at 100% health.
(2) Shortly afterwards there was another random load screen: The walls reverted back to around 75% health, as they had been before.
This clearly doesn't seem quite right. Ideally, of course, there shouldn't be any load screens at all. Perhaps, though, this sheds light on why they were erroneously happening. It happened while the opposing faction was taking the mine. All other resources and the keep were owned by us and not under attack. The reversion happened roughly when the other faction had completed taking the mine.
PC EU: Magblade (PvP main), DK (PvE Tank), Sorc (PvP and PvE), Magden (PvE Healer), Magplar (PvP and PvE DD), Arcanist (PvE DD)
PC NA: Magblade (PvP and PvE every role)