Suppose a man had a quarrel with his wife/girlfriend and in the
heat of the moment he slapped her. She goes to the police to make a
complaint. Should the police arrest the man and bring him back in
handcuffs for investigation into the allegation of 'voluntarily
causing hurt', 'cos that's what it is? Should we make the police
arrest every husband who slaps his wife, mother who slaps her
daughter and siblings who hit each other in domestic
disputes?
That is why the law makes a distinction between serious 'seizable'
offences which empower the police to arrest and investigate without
a warrant versus less serious, 'non-seizable' offences, which
require a magistrate's warrant to proceed. This has been enshrined
in our law and is not peculiar to us. Malaysia, Britain and many
commonwealth nations have similar practices. Such a distinction is
also necessary to limit the powers of the police and so safeguard
civil liberties to prevent overly draconian police actions.
The list of 'seizable offences' is listed in Schedule A of the
Criminal Procedure Code. Causing grievous hurt is a seizable
offence whilst voluntarily causing hurt is not. The difference is
in the time-honoured, legal concept of wounding. A wound in law
refers to a complete break of the skin (an abrasion or a bruise is
not a wound) or damage to internal organs and bones, such as a
fracture. If the police had arrested someone for 'voluntarily
causing hurt' without wounding, the officer would have been guilty
of wrongful arrest.
In this case, the police misclassified it because not being a
doctor, the officer did not realize there was a fracture. However,
as the victim was bleeding from the nose, he should have deduced
that there was likely to be a full break in the skin somewhere. (In
this case, the break was in the nasal mucosa, not the skin as we
commonly understand it, but the courts may accept the mucosa as
equivalent.)
As to the issue of why the police arrested the cab driver who
struck the MP during his MP surgery (or 'Meet-the-people' session),
that's because 'voluntarily causing hurt to deter public servant
from his duty' is a seizable offence in para 332 of the said
Schedule A.