BA staff seem to claim that lots of things are the law when in fact it is only them that do it. I don't understand why BA staff think they know better than FF pax what other airlines do.
Qantas staff have very similar attitudes. I had a ludicrous situation at check-in in Sydney the other day where the woman insisted that I extract may laptop from my roll-on bag, and then shuffle items backwards and forwards between the laptop bag and the rollon until the rollon was less than 7kg. It didn't seem to matter what weight the laptop bag was. Of course, as soon as I walked away from checkin I just put the laptop back in the rollon and everything was fine.
When I pointed out to the woman that enlightened airlines like CX don't mess customers around like this she tried to insist that this made CX an unsafe airline. Of course, in the real world what it does is make CX a very profitable airline and Qantas a bit of a joke, protected only by monopoly and government regulations.
This was all at a First Class checkin desk as well, where it took the first couple of minutes to get her to recognise a OneWorld Emerald card.
To be fair to Qantas, the man looking after the First Class Qantas Club had the decency to allow me to bring in three guests since the lounge wasn't busy and two of them were about to suffer their third consecutive overnight flight in coach. This was much appreciated.