The SOP on the jetway for UA flights out of HKG is everyone who has a carry on bag gets "searched". Oftentimes the search is nothing more than partially unzipping one zipper, pretending to look inside, and then rezipping. My bag usually gets "checked" in under 15 seconds from being set down on the table to being waived on (and most of that time is due to a sticky zipper). And my second carryon (a laptop bag) rarely gets looked at.

They do occasionally spend more time and dig deeper depending on profiles, pax reactions, pax volunteering up liquids, random spot checks and/or their level of boredom. But overall it's just theater.

You'd have to be pretty incomptent if you really wanted to get something past these jetway checks and couldn't.