Unless they changed it again, you do get the Light from either choice, but you don't actually physically pick up the item like you do in the other situations.
These are the five questlines you need to complete to get all the Lights of Meridia:
Haj Uxith — Determine the fate of Haj Uxith's Hist tree.
Library of Dusk — Discover the fate of the lost scholars.
The Moonless Walk — Rescue the Fighters Guild from the Moonless Walk.
Tower of Lies — Rescue the Fighters Guild members from the Tower of Lies.
The Vile Laboratory — Help Gadris and Zur reverse the soul-meld.