Just save your claymores in corners of the war room, and leave a crawler when the thief is going to show up (should be every five rounds after he first appears). Then line the claymores all around the catwalk area above the war room and lead him into them about 10 properly placed claymores is usually more than enough to take care of him. You could be noob about it though and just eat a grenade while you have quick revive and blow him away with Mustang and Sally, but I don't recommend it.
I don't see how using quick revive and downing yourself is a noob way of getting the trophy. If you go on youtube all of the videos of getting this trophy show them using the quick revive trick to get it easily.
PSN: CaTaLySt_K1LlEr Black Ops Zombies: Round 57 Solo on Kino, Round 34 Solo on Five