Regardless of Park Yoochun's crime, you should listen to this critic objectively.

He mainly talks about the difference between Park Yoochun'sinterrogation and the others', how he must had been treated according to the law etc.

Some quotes:

-"The first human rights violation is that Park Yoochun said he would join in the investigation voluntarily, so the search and seizure is not necessary. The first step of this case is already confiscating the property and body as the coercion. Regardless of this case can be done in bail, the police still put this person under detention for investigating. However, they said that the reason they need to detend one person only to avoid he/she escaping and destroying the evidence, right? That's why they detend him/her. Park Yoochun requested to be investigated and joined in the investigation voluntarily, so did it seem like he wanted to escape? 

-"They said they have to arrest him in order to prevent him from destroying the evidence. If so, why they still have to search uninformed thoroughly his house and confiscate his property? Clearly police have searched though but they still couldn't find any proper evidence. If police haven't found an evidence, it means that they can't the amount of drugs which they claimed to be in his house and car, right? And when they couldn't find anything, they announced that 1 gr of drugs missing is going to be found during investigation. 

-"Police used *PHOTO LINE* for Park Yoochun."

Photo line is known for being used for politicians, chaebols, in-power or retired high level officers,  
in-power and high level officers in journalism and former presidents. They have to stand in front of the yellow line and put their hands together, which means, "I apologize to every citizen of our nation. I'm afraid of the public's anger and I will sincerely cooperate with the investigation."

-"Talking about Photo Line, this is something very violent. When the case still wasn't clear, they used photo line since the very first investigation steps. If they use it for Park Yoochun, then they should use it for any other civilians as well. Photo Line is only used for the official criminals. 

-"The thing which violets his human rights most is that they used rope to tie his hands. Rope can be seen easily, so the media had to censor his hands in the photos but some bad journalists just published the raw photos without censoring. They applied the arrest warrant while the case still was being investigated and the fact that they used the rope to tie his hands even before the official confinement is an act of violating several human rights at the same time.

-"Looking at the drug testing process, it was too fast. Drug testing normally takes 2-3 weeks to be done but in Park Yoochun's case, it took only 3 to 4 days.  It's possible to produce the results but it's not a detailed result. To make a clear conclusion through intensive testing, it must take 2, 3 weeks. But the police gave information about the results through the media in only 3 days and arrested Yoochun less than a week."

-"They gave Hwang Hana a lot of considerations but Park Yoochun hasn't got any. Police released Hwang Hana the last time she did drugs. After she was arrested for investigation, they focused on Park Yoochun again. Before that how did Hwang Hana use drugs, who took drugs with who, people forgot it and focused on PYC. As outsiders, people only know those informations because they can only see what the media want them to see. In the mind of Hwang Hana's side, they put all the faith in police. They thought that the words Hwang Hana said were all correct. But who is Hwang Hana? A drug user, seller, a criminal. Can her words be such trustworthy? I have a feeling that police secretly hide things for Hwang Hana."

(quoted some parts till @11.24)

original source: