Yeah as the title says, how did they both end up there? At the end of the quest chain I remember very clearly (since I spent about 10-15 min agonizing over who I should leave behind) that you had to choose one of them to become traped inside of the Temple of Mourning Springs. Imagine my surprise when I found both of them in Elden Roots' mages guild perfectly fine and unharmed without any kind of explanation over HOW they got out.
For all I care they could have blown up the temple, summoned Akatosh himself or became vampires and ate Uldor somehow. I really don't care, I just NEED to know because right now it feels like they just went "Whaaat? You thought I was trapped forever? Hah! I freed myself within 15 minutes after left after you left along with completly destroying Uldors soul, something you couldn't manage. Noob!" and it's driving me freaking insane xD