What happened is the following :
I have in play Timmet son of timmet and a cersei's attendant. Valar Morgulis is played (Timmet is standing)
Action is initiated, no save.
Phase 3 both characters become moribund (dead)
phase 5, response from the cersei's attendant, Timmet is knelt.
phase 6 moribund cards leave play physically, but Timmet is cannot be killed at the moment.
In the faq there is a rules exception under moribund at page 16 :
However, the "state" of a moribund card can be changed by an effect that does not actually attempt to remove it from play a second time.
I have difficulties with this sentence, does it mean that the state of timmet could change and not die ?