What LoreRaider said. To put it another way, your GlobalTrigger was saying "If TG 12 is true, do TG 10, otherwise do TG 11". That meant it was trying to remove the questitem only when the questitem was not in the inventory...
I should also point out that your globaltrigger is currently executing constantly. If you just want the globaltrigger to trigger once, you should use FGT_SINGLE_SHOT.