My level 75 Shaman (Aradune server) with Challenger Perk lost level 75 after dying while being a shrouded 70 rogue. Thanks.
That is why I opted to die in shroud for the free port back to PoK after picking up a quest. When I took off the shroud my level was 94% into 74. I ran back to my goblin rogue corpse to rez it, and got my level back. I even checked my account to make sure that the perk was still active which it is until it renews in August.
Spirit shrouds have an AA called "spirit sending" which will send you back the the npc who shrouded you. No need to die. Just for future reference.