Exactly. Jiho had no Idea because InWoo instead of telling him he did not want to see his mother and explain to him why, made him do something; trying to help at that, that ended in the mess They are now. They are both at fault. Not only Jiho.
Jiho was raised in a loving family where talking and having communication fixes thing whilst InWoo did not. Jiho did not know the whole story so then why is it his fault when out of the goodness of his heart and feeling helpless not being able to help when seeing InWoo in despair not long before all the mess was the only way he thought to help.
We as human tend to do things and sometimes it doesnt help but make things worse this is what happened here. It was just a simple human error, a sad mistake. A Misunderstanding.
I was pissed when "but she is still your mother" no boy you have no idea