When you perform a finishing move in sitting and just as the animation is ending at lighting speed your body reverts back to just looking straight. It's not just a one time thing it happens all the time watch gameplay videos you'll see it. It looks so jerky and awkward... I wonder what the reason it has for doing that? Its not smooth or elegant like finishing moves are supposed to appear.
This is a videogame, and considering how well these games have progressed since TES I Arena, your complaints are borderline childish. I for one, am amazed at how awesome everything looks, even the jerky animations. If I can enjoy Morrowind, which is so much worse with animations, then why would this matter?
If you want to see awesome finishing moves, then play an action game with no roleplaying depth.