Because it's so expensive to raise kids nowadays...parents treat
their kids as little princes/princesses....cannot beat, cannot
scold, cannot shout, cannot anything... 
And just something to take note of, if that kid's father is also a
teacher there, better beware when you are telling him about what
the son did. He may just go defensive and insist his son didn't do
such a thing.
Remember, school's over. The kid may go home tonight and tell his
father that he pwn you today. The father may already be prepared on
how to reply back to you shall you go complain to him...
Just be careful, you just kanna by the son, you may just get the
same treatment from the father.
Welcome to Singapore. 