The people in the gospels were still under the law.
So, if a child disobeyed/disrespted his or here parents it would be ok if they were stoned to death? When did it become ok not to do that?
God chose Israel as a special people. He showed them a special way to live apart from non believers. As a
child grows up he may see these things in his life;
Foolishness is bound in the heart of a child; but the rod of correction shall drive it far from him.
Even a child is known by his doings, whether his work be pure, and whether it be right.
13 Withhold not correction from the child: for if thou beatest him with the rod, he shall not die.
14 Thou shalt beat him with the rod, and shalt deliver his soul from hell.
The rod and reproof give wisdom: but a child left to himself bringeth his mother to shame.
My son, keep thy father's commandment, and forsake not the law of thy mother:
He that spareth his rod hateth his son: but he that loveth him chasteneth him betimes.
If this fails and he grows up to be a man then
18 If a man have a stubborn and rebellious son, which will not obey the voice of his father, or the voice of his mother, and that, when they have chastened him, will not hearken unto them:
verse 18 is speaking of a grown son
19 Then shall his father and his mother lay hold on him, and bring him out unto the elders of his city, and unto the gate of his place;
20 And they shall say unto the elders of his city, This our son is stubborn and rebellious, he will not obey our voice; he is a glutton, and a drunkard.
verse 19-20 explain the grown childs actions ( certainly not God-like actions )
21 And all the men of his city shall stone him with stones, that he die: so shalt thou put evil away from among you; and all Israel shall hear, and fear.
verse 21 is living up to being a special people called by God to put away evil away from them, even if it is your son or daughter.
So first it is God and second it is your child any other order is wrong. It appears they were not stoning children as your post implies. This was a child that had grown up and still wanted a sinful life so they being called by God had to put sin away or out of their life. This child you speak of may have had 20 or more years to comply with his/her parents and God.