"You can't make me!"

It is the second time I have heard a child say this to a teacher in the past week.
On the first occasion the child was one of a group of those in their first year at school.  They were on their introductory visit to the local library. 
He was clearly familiar with the library. He had raced off to find books to read. The teacher was trying to haul him back to be told about something he already thought he knew all about. There was a discussion between the two and he sat down in the group. A bit later he was "helping" the other children. The teacher had probably handled the situation well.
There was a second group of much older students going somewhere yesterday. One of the boys was deliberately walking out into the road when he should have been walking along the footpath. The teacher told him to get back onto the footpath. He refused.
    "You can't make me."
The teacher stopped the rest of the group. There was apparently a train to catch somewhere because I heard something about "miss the train" as I waited to pass the group.  
He stood in the gutter and refused to move. I could see the other children getting anxious. 
      "You can't make me!"
      "If you don't get back on the footpath this minute nobody will be going anywhere."
There were mutterings among his classmates by now. 
      "All right everyone, turn around. We are going back to school."
There was, rightly, an outcry.
At that the boy in question turned around and walked slowly to the end of the line and up on to the footpath. He was smirking as he did it.  The class went on to the railway station. I hope they caught the train.
I wonder how the teacher followed the incident up. Would he have followed the threat up if the child had refused to move? What if the child had still refused to move from the gutter? 
Someone else waiting to pass said to me,
     "He deserves a thrashing but you can't even touch them now."
The boy obviously knew what he was doing. He seemed to know exactly how far he could go. He was handling the teacher rather than the teacher handling him.  
I wonder what I would have done. 
When the Senior Cat was a headmaster it was still legal to "cane" a child. He reserved it for two offences. One was throwing stones and the other was gross insubordination to a teacher. He hated doing it, so much so he would come home with a violent headache. The occasions on which he did it were very rare. I can't remember him doing it when we lived in rural areas. It happened perhaps three or four times when he had his city appointments. 
I never had to send a child to the head. On the one occasion one of them was extremely rude to me his classmates let him know what they thought immediately.
     "You should apologise right now!" he was told. 
There was a mumbled apology and I let it go. The next morning he turned up at school with a single flower he had bought from his own pocket money. I never said a word to his parents or the head of the school.
That was a long time ago. The male teachers wore a collar and tie to school and only took their jackets off if it became too hot. The female teachers, including yours truly, wore skirts and dresses. It is unlikely the children even knew our given names. The parents addressed us by our surnames as well.
It isn't the same now. I keep wondering how I would have handled that boy yesterday.