Nice one Phil!
You've sold me on that one.
The only thing that strikes me as a missed opportunity is the final resting point of his eyes.
When animating, animators often draw an X where the characters eyes are focusing and keeps the characters eyes on that X as much as possible. In Animation:Master we often do this by creating a Null and having the Eyes follow that Null as an Eye Target. This is usually accomplished with an 'Aim at' Constraint. Of course the challenge with any Eye Target is to understand what the character is trying to looking at. As it is something going on inside the character's mind that something is important and even if never seen by the audience we should define it. If the eyes go somewhere else... there's another X for you to define.
I sense that if you cannot get his eyes to open wide enough, or don't have an eye target in your rig, you may have to tilt his head back up for us to get a good look at his eyes. Bottom Line: The audience wants to see the character thinking and this is best conveyed with the face and particularly with those eyes!
(Going back to watch it a few more times.... standby...)
I see a couple possible courses of action and I've listed them in order of my own personal preference. If this were a shot from a director, you might not have the option to add more time or insert another shot. You'd have to really sell that extra footage to the director as that forces changes all the way down the production pipeline. I assume you are the director in this case so it's your budget to decide.
1. If this scene hooks up with another shot, for instance a close up on the character's face, I think this shot is good to go to final refinement.
2. Add more time to finish the final beat of this sequence. Really nail his recovery. Have him look intently up to the source. (See previous comments in previous post on this subject for some ideas on possible emotional performance options)
3. Quickly change his expression at the very end. Pop from one expression directly into another. He's shaken his head... but now he's back and you've got to sell what is emoting from his mind. (See previous comments on anger, etc.)
4. Some other thing I haven't thought of that can really sell the character's performance. In a gag this would equate to something completely unexpected and without knowing more about what happened to motivate the push this remains something for you to define.
There is one other thing I would do that is unrelated to your animation. I would do something with the background.
I will often replace the default Ground Model with one of my own that curves upward (to soften the horizon) and/or slightly arches it so that it isn't a completely straight line. For me, altering the color and inserting other objects is a secondary consideration to just breaking up that boringly static horizontal line. You've put a lot of time into this animation... don't let distractors like a default background degrade that... make sure to present it right. Heck, if you are really ambitious put a couple stacked boxes behind the character and have them interact with them. Perhaps that is what slows/stops his backward fall?
Great update Phil.
Keep em coming and if you have the spare time try some variations.
You'll get faster each time.