Kim Dotcom's company was registered in Hong Kong, but Kim and his office were in New Zealand.

Yes and the raid of his company illustrates the high level of cooperation between HK and U.S. law enforcement, and that was only over movie downloads.

There is a difference. China isn't too interested in a trade war over copyright infringement, but it is also an up-and comming world power, so they might decide that the propaganda win is big enough that they are going to keep him.