Hi Takkers,
Yes I am from overseas but I do hold a HKID.
I don't think Dragonair do send out email to the rejected candidates. I know a guy that didn't pass the English and Number Reasoning tests he never received a call (obviously, since he didn't pass) or email. I am pretty certain that I didn't pass the aptitude test as they told me to wait for the result within a week but I haven't heard anything...
However I am having my Stage 2 with Cathay soon, so fingers crossed!