[Bigg Red]

Could anyone do that punch? Even a woman? It looked like he hit her firmly but not as hard as he could have.

[xone]

https://www.youtube.com/watch?v=XiEvjntQBuk

Try this instead

[bigbob]

THe guy who whupped Corn Pop could have ;-)

[Cletus.D.Yokel]

It was well aimed, right at her chin.
Watch her on the pavement.
She wasn’t knocked out, just stunned.

He compressed the nerve at the jaw-joint without breaking her jaw.
It can be done.
Ask the guy from the N.Shao-Lin.
As my sensei told me, “Technique, technique, technique! Now, 500 kata.”

It is also taught in other fighting like boxing.
A strike to the lower jaw at the joint, lift and push the head back.
Lights out.

[meadsjn]

Could anyone do that punch? Even a woman? It looked like he hit her firmly but not as hard as he could have.

Yes. It doesn't have to be as hard as other locations to produce a knockout. It just takes some knowledge and a little practice.