I also tried different things to push his expressions, and one of the things I did, was scrap the second pull of the door. I replaced it with him trying to push it open with his shoulder. This way it seems less staged and calculated. In reality, if pulling didn't work, you'd try to push.
I added much more facial expressions and made sure no part of his body was frozen in time at any point. One critique I got was that when he slips off the door from pulling, we only know he's going to do it because it's logical. So I tried to add him hitting himself in the face with one arm which serves as a waypoint to the rest of the body to follow.
Lastly, after he regains his balance, I tried to add a small head shake to get more of the "gotta get my balance and retry this" kind of pose.
Hopefully these changes turn out to be for the much better.