YouTube 拍DSE片的版權問題

Yes - you are correct.

Since HKDSE is a "product" by HKEAA, HKEAA has the ownership of the copyright.

Any unauthorized duplication can be prosecuted, both criminally and civilly.

(Many people doing it does not mean it is legal.)

2015-01-12 14:52:04 補充：
Not in Hong Kong.

If it is copyright-free for education, why does HKEAA need you to pay for the past papers?

好像教學用途是例外。