Specter stripped of dark shroud on mission exit

[srmalloy]

Leveling up a new Necro/Marine MM, I exited a mission with a Specter active (summoned by the use of Gloom), and the dark cloak/invisibility visual effect on the Specter was stripped away, leaving it looking like an ordinary CoT ghost:

 

 

It didn't affect the mob's actions, and the Specter despawned at the end of its 'life', so as it doesn't affect gameplay, unless someone happens across an easy cause and fix for the issue, it should get put behind more gamebreaking bugs in the fix queue.