The killcam itself lags, especially the audio. But sometimes it doesn't even show the kill, it shows your killer running up behind you and then it ends, or sometimes you just see a guy sprinting down the hallway, not even spotted you yet, and it ends. From the looks of it maybe the system is timed, to about 5 seconds or so before you were killed. Maybe this is the same way CoD killcams work, but I have never seen this happen in CoD.
Sometimes it shows "killed" cam, the view of the guy that was killed. How this happens I really cannot understand, unless the game was confused about who killed whom.