We don't have all the facts, but I'll make a few assumptions in a hypothetical scenario:
- Daddy rolls up to airport with daughter & friend. Daddy's a Goldie CIP and booked in First or Club while the girls are non-status and in 3rd World.
(Actually, they pitch up late for advertised Y-cls c-in, based on Daddy's ability to c-in nearer to close (due FFP status and class));
- bookings are not linked;
- boarding cards are issued, but flight is oversold.
- after c-in closes, at the gate a manifest is printed, which contains FFP status but not DoB (so the gate people don't know individual paxs' ages). Girls are not identified as UMs in t heir booking because they're travelling with Daddy;
- based on the manifest, status CIPs are guaranteed boarding; volunteer call may have gone out but didn't result in enough losses so bumping starts;
- girls are bumped by the gate agents and are called to the gate desk - they're probably expecting a U/G at this point but instead are told they're off and go running back to Daddy, in tears;
- Daddy steams up to the gate desk, huffs & puffs and demands the girls are not only not bumped, but are U/G-ed; when it's ascertained out that he is premium traffic, status CIP and they're in one party, some rejigging is done and the girls are given seats (as BA has said). Girls are probably not U/G-ed (as premium seats already filled by revenue traffic and status CIPs) so Daddy gets the hump and decides to fire off a blast to WW.
My personal correspondence to an erstwhile airline CEO didn't make the papers (it was actually entirely praiseworthy - actions well above and beyond the call by a couple of ground staff - and I received a personal response); I have to be cynical as to the source of this 'news'.
We've all been there, mate. The staff are usually trying to do their best to accommodate everyone they can but have to deal with ******s from time to time. As for overselling, well BA isn't the only show which does that and they wouldn't feel the need to if everyone showed up.