The police didn't quite admit the fault. If you read in between the lines in Chu's public statement.
He implied:
If the 2 guys clearly indicated that they were police, they are not necessary at fault. Besides, Chu also didn't say that 吳耀偉 didn't strike out. He just said that it was too early to draw the conclusion.
It's natural to hire "TYPE A" people in the police force. and "Type A" people are prone to this kind of problems. It's like saying, let's hire cowboys to be police, but let's hope all the cowboys behave.
on the flip side, if they don't hire "Type A" people then they will not be effective when needed either.
(same logic applies to the army. Look at what the US troops did in Iraq. Look at how US government defend their troops when they did horrible things!)