People see what they want to see, however you can clearly see in the video an exact demonstration on issues with the physics calculating damage improperly. likewise in the arena more times then I can count, a sword/mace barely brushes me while barely moving and I somehow take a sever critical. Further evidence can be seen with two-handed swords clearly moving fast and doing nothing more than pushing a target.
On average a sledge hammer weighs anywhere from 4 to 20 pounds with its mass focused on the head, whereas the two-handed sword weighs anywhere from 4 to 40 pounds (heavily dependent on type) with the AVERAGE being 10 to 20 pounds...all this considered I can't count how many times I've swung and raked a two-handed sword across an enemy and done nothing! (must have plate armor under that tunic?)
I'm still fairly clumsy with my controls so 90% of my swings are exaggerated, fast power swings so I find it extremely hard to believe I don't lob AI's legs or head off constantly, and on the subject, I also can't see a zombie blocking a 10 to 20 pound sword that is heavily swung with his wooden chair leg (or even a small wooden buckler), so there are issues with blocking as well.
If you still need more proof do what the thread starter did in his video, both without swinging, and after performing the swing+run as he mentions.
I bumper car AI's all the time (not after swinging) and rarely even push them down, let alone clobber them accidentally, alternatively the AI swings at me frequently, so when I bumper car them after a swing (like how boxers hug to prevent hits) I take a magical critical hit from a weapon that can't be swung (due to the hug).
And please don't misunderstand, I'm not bashing the game, I just want to see it get even better!