Light does not prevent endermen spawning in The End

Verification builds:
1.2.5.15 Retail

Summary:
Light does not prevent endermen from spawning in The End

Steps to Reproduce:

1. Travel to an area over the void in the end
2. Set difficulty to Peaceful
3. Place a single layer of end stone, and cover it in torches
4. Set difficulty to Hard
5. Wait for mobs to spawn on the end stone platform

Observed Results:
Endermen will spawn in even though the area is covered with torches.

Expected Results:
The elevated light level should prevent mobs from spawning in.

Screenshots/Videos attached: Yes

Notes: