Yang Biadap Gobalakrishnan Attacked Police Officer?

I missed the Prime News yesterday evening, but managed to catch the video on You Tube.
Biadap, Uncivillised & Kurang Ajar is the most appropriate word to described the act of
Yang Biadap Gobalakrishnan Ahli Parlimen PKR Padang Serai:

I'm confused why did the Police charged Gobala with obstruction instead of attacking a Uniformed Police Officer.

Has the Officer made a police reports for the slapped.

Someone??