I just had this exact same quality issue with "The Live Of Others".
Now, an interesting and possibly significant detail: when I freeze the picture and step forward step-by-step, 3 "frames" (not sure if this is the term I should use here - don't know if it shows it frame by frame) are alright, then 2 bad "frames" with the "lag effect" showed in the pictures, then 3 good ones, then 2 bad, then 3 good, 2 bad and so on.
This leads me to believe that Dan203 was right above, with his suggestion that it has something to do with the frame rate conversion when the video file was created. I think I should ask and see if Amazon has any plans on fixing this...
Either way, be warned that "The lives of others" on Unbox have this defect.
EDIT: added the screenshots of the step-by-step forwarding here, note the 3:2 sequence. After this sequence, it started over again with 3 good ones and 2 bad and so on. Look at the wheel housing on the car, and you'll see what I mean.