The calculation is very important. From that linked Government release: "(i) five or more passengers, or five per cent or more of the total number of passengers on board the same flight (whichever is higher) tested positive for COVID-19 by arrival test."
That is, if there are 60 passengers on board the ban will be triggered not with 3 positive cases but with 5? And with 200 it will be trigerred not with 5 positive cases but with 10?
Of course with a larger passenger load the greater the chance one passenger will have non-compliant docs and the second 3-positive-cases rule will apply.
“ii only applies *if* one non-compliant case boarded aircraft:
“From May 1, if on the same flight there are (i) five or more passengers, or five per cent or more of the total number of passengers on board the same flight (whichever is higher) tested positive for COVID-19 by arrival test, or (ii) three or more passenger are tested positive for COVID-19 by arrival test and one or more non-compliant case(s) was/were allowed to board for Hong Kong without complying with with the requirement(s) specified under the Prevention and Control of Disease (Regulation of Cross-boundary Conveyances and Travellers) Regulation (Cap. 599H), the passenger flights of that route from the relevant airline from the same origin place will be prohibited from landing in Hong Kong for five days.”
https://www.info.gov.hk/gia/general/...2042200621.htm