The post I was quoting is about EXITING Hong Kong, so was my comment.
Many people can access the electronic gates for visitors, and lines for manual check are quite short. But even when they look long, they go very fast for departure immigration.
Similarly, security lines can look long, but they go very fast at HKG, unlike many other airports. And there is no discrimination between HK residents and others.

Ah, quite right Brunos, mea culpa – and agreed, in my experiences the exit process is indeed quite speedy.

(Whispers: shouldn't this be in the Hong Kong forum, not Cathay?)

Normally I would agree this is more suited towards the HK forum.

But given the cause of this 'incident' was OP trying to use CX's departure lounges and got 'stuck', this forum is fine and serves as a good warning to anyone wishing to attempt the same.

i did this mistake today..
went to brush my teeth at the PIER.
When tried to leave, they sent me to information CX desk but it was busy so i went to the WING lounge where the CX staff called a staff member who escorted me to arrivals through backrooms..

If i knew, i wouldnt do it.. but it never crossed my mind since my experience around the world was mostly positive.

Many airports around the world operate the same as HKG. I would always assume you can’t exit once you decide to clear security. Of course, exceptions can be made at HKG airport but it is rarely worth the risk or the hassle.

Why do many like to assume

I'm surprised they (immigration) let u out. What's your excuse? Wanting to explore the city doesn't seems legitimate enough.

Not sure why you are surprised. If you were to read this forum carefully you would see MANY of us have done this, for various reasons! "meeting a friend". "doing some shopping". "getting some sleep". Not sure why they would care as long as you have the right passport etc.

Because this is a criminal offense in Hong Kong for entering departure floor with "no intention to fly".
Your name and reason for leaving the departure floor has to be passed to the Immigration and sometimes the HK police.

I’m sure I’m not the only that can picture the logistical nightmare when many people in transit decide to go to the Pier for a shower then ask for an escort to enter the city.

Well yeah technically you could be fine, but that doesn’t mean you should push your luck. Personally, I wouldn’t chance it but being stuck at the pier for a few hours is not the end of the world. :p

The problem is that you are not supposed to. You want shower there are public ones on the arrival floor.

HKIA should throw these people down south in Stanley

Under what law or ordinance? I've heard this is illegal in Singapore but have not heard of a similar rule in HK before.

Please scroll up to https://www.flyertalk.com/forum/36083369-post59.html

Thanks PaulC852 for the pointer. Reviewing that, though, whether a passenger is able to rely on s.5b (they are arguably an "air passenger awaiting an onward flight in any area reserved for transit or transfer passengers which is within a restricted area" - what may be in dispute is whether they are bona fide), that requirement is seemingly mitigated by s. 5(2)(c) thus: "being a departing passenger or a transit or transfer passenger, he is in possession of a valid travel document and a valid aircraft boarding pass" which they are.
I am not condoning going through transit to use a lounge then asking to go through departures: I think it is selfish and bad form. I am, however, curious as to whether as suggested this is an offence in HK. Singapore - a very pettily governed place in my view - has such a legal rule and prosecutes, but has anyone been prosecuted for this in HK?