There is no way to complete this quest with no bloodshed, and anyone that says wear a full imperial legioneer set again im going to kick in the head! There is no legioneer set in the game, you cant get the leader of the imperials to release him, and you cant sneak in without failing the mission. I just want to make sure this bug is known about and hopefully some time will be taken care of.

When I did this mission, the Thalmor automatically attacked me causing the objective to fail, but the mission continued and let me rescue him and complete it.

It seems as though Bethesda had originally intended to provide a peaceful solution, but discarded the idea. Working as intended?

Somone said there is a missive ID in the game that states to let the prisoner go, though there is no triger for you to get it, therefore I belive its bugged, and it would be stupid to put in a mission that cannot be completed properly.

the devs should have left out the peaceful solution to avoid people having the unfinished quest...

From what i've read the imperial outfit works only after you have joined the imperials and completed the quests then talk to the general who gives you some sorta release paper.

What's the point releasing a Stormcloak supporter if you have joined the Imperials?

Double agent.

Ah lol, ididnt know u had to be a legioner to free him. I tried to sneak, tried to persuede but nothing. So I took my blade and some thalmor heads started to roll on the floor, its also a good way to negotiate =P

That doesn't work for me. I've joined and finished the Imperial quest line. Tried talking to Tullius and he just tells me that it's impossible due to the problems it would cause. Tried dressing up as a legionaire to bluff my way past the guards but I get no extra speech option from doing that....

Even tried dressing as a thalmor (I'm even a high elf) with no success