Simulacrum up and still dying

I know that there is a cool down for the cheat death skills. I have noticed a few things with them. Final service and the Enchantress fates lapse proc at the same time and the Final service usually overrides the fates lapse. The other thing I have noticed is that with the Masquerade set your Simulacrum is supposed to get all runes. One of the runes says that if your simulacrum is up and you would die, the simulacrum dies instead. I have died multiple times with the simulacrum still up. I am not sure that the rune is being applied.