It is never, ever, ever acceptable for a husband to punch his wife.
The fact that he knocked her out makes it worse.
It is never, ever, ever acceptable for a husband to punch his wife.
The fact that he did it in front of their children makes it worse.
It is never, ever, ever acceptable for a husband to punch his wife.
The fact that he didn't acknowledge that he did wrong, but instead irritably told her to get up - makes it worse.
I sometimes leave a MN window open on our computer, and DH often reads threads I'm reading, because we like talking over stuff together. (Often ideas of stuff to do with DS, or laughing at stuff, whatever.) He read the OP and was genuinely shocked at what J's husband did to her -truly upset and worried for her, and horrified that her 4 year old daughter was so frightened...
What J's husband did is shocking. No amount of violence is acceptable, to me - those that love, don't hit - but I have never read an OP that made my blood run cold like that, and DH actually said "I had to stop reading when she mentioned her little girl, it was too awful."
He checks in with me sometimes, "I lost that thread, is she okay? Is she still safe?"
I give you this insight into our dull little life to point out that, whatever J is being told by whoever, it is bad, wrong, horrifying and totally unacceptable that her husband knocked her unconscious in front of their children. She didn't MAKE him, she isn't responsible. He lifted up his hand and threw it at her. He chose to do that.