Earlier quoted context omitted.
How did you come to a conclusion that randomly arrested two people? Double standard?
Different systems and real differences. China does not have the rule of law or separation of powers like western countries have. In the west it's not easy for the executive branch to interfere with individual cases. US or Canada executive branch can't just tell justice department to arrest someone. In China that's possible and common.
A quick look at Wiki suggest that there's at least some aspects of rule of law in China (1) - although with some defects.
I don't have the background to compare these defects with those of any other country (like the US's high incarceration rate (in general, and of minorities specifically)). I have lived a few years in China and Hong Kong and know a few lawyers and accountants born/working there. This experience has left me with a generally positive outlook.
I always try to keep in mind that my experience is narrow, but, sadly, people often have absolute opinions with even less experience, so it's always hard to gauge. I'm curious if this is a field that you've studied or work in specifically?