This is incredible incompetence. Houston police apparently attempted to pull over a car driven by a Chinese diplomat. They pursued the car into the consulate's garage where they handcuffed and arrested the driver injuring him in the process.
While I would suspect that the Chinese diplomat may not have behaved in the most conscientious manner by driving aroudn without a plate, this is over the top incompetence by police officers. Diplomatic relations are always somewhat delicate and you'd think that police officers would become familiar with consulate locations to prevent this kind of thing from happening. Even if the diplomat didn't make his status clear, you'd think that there would be some kind of hint that something was off to cause the police to act with extra restraint. There really isn't any excuse for this kind of thing.