About this.
It looks like Pose Stiffness = 0, which would allow limbs to twist infinitely. To roll around itself, like it’s doing on it’s way down.
Typically, for any ragdoll that is completely knocked out, you’d still want some stiffness. Something to keep muscles still connected to the bones in your body. You’ll notice that every limb in everyone’s bodies have a “preferred angle” when completely relaxed. It’s the angle they get when every muscle is at their natural length. For example, the angle between upper and lower arm is around 45 degrees. That’s a result of the bicep pulling on the arm being slightly, and the tricep also pulling on the arm slightly. They are basically both too short to keep the arm either completely extended or completely contracted. And it’s that tension that keep the arm at 45 degrees with some Pose Stiffness.
The same is true for just about every body part.
On top of that, there does not appear to be any limits in this character, which would also help prevent unnatural angles like the knees and feet here. Muscles do their part in keeping things at a preferred angle, but our bones do what muscles cannot, like prevent this twisting motion.
So as a simple improvement, leaving some Pose Stiffness - whilst ensuring the animation has come to a stop, keeping a static pose - would resolve the twisting issue and generally make it look a little more believable. That could then be taken to another level with limits, at least for elbows and knees.
With regards to the pins on the hands, have you tried achieving this result without pins? E.g. just leaving everything local and see where the animation takes him? You could potentially have a very very gentle pin on the torso to guide him along. At the moment, it seems to me that the hands are pulling on the body bit much.