Teachers should be better trained. They should be trained to
deal with people rather than trained to deliver lessons.
The teacher missed the telltale signs.
A student banging a book on the desk repeatedly, dispite
being told to stop. That should be the clue to something is
wrong with the student. The teacher should address whats
troubling the student rather than tackling the nuisance.
The student is seeking attention.
The student is bored.
The student is angry, (at something, parents, bf, school,
etc.)
Find out what, instead go and disturb the student somemore, and
kena whacked.