Never got an answer in the QQQA thread, so here goes.

When the player has entered an animated state (in this case the knocked down state from when Karliah has shot you down), how can I return the player to a normal standing position without playing the stand up animation?

There's an Idle you can play to stop animations. Offset_Hands or something random like that. Not sure if it is standing up? If not, that could work.

IdleStop_Loose is a good one to use.