I also had a issue that after the dead anim the skeleton goes back in Tpose…I solved like this:
get last frame of your dead animation, create a new animation from it with just 1 frame (it will have the body dead on floor), then play that anim after the dead animation and tag Loop to True. In this way the skeleton will die, play the dead animation, then if needed put a delay N sec (N=dead anim length) and when done, play the new anim in a loop.