yep the bit about BA staff moaning about "cheap tickets" ex-EU is laughable - it is their own fare structure, and their own decision to allow B2B (which they really have no real grounds to prevent)
plus how do they know whether it's even a real B2B or a genuine arrangement - if I have to go to the US, I might deliberately schedule an overdue trip to DUB or CPH to see friends or whatever to get a better fare; if, as I do, I take my wife & kid over to see family Germany whilst I am going away on business...that "looks" like a B2B (LHR-HAM on the evening of Day 1, HAM-LHR-US on the morning of Day 2; reversed at the end of the trip) - but that's a totally real trip - I would be FURIOUS if I got stick from BA staff for buying a "cheap ticket" on that basis...it's a legitimate ticket, from your own pricing structure...and by the way it's still a €1,900 fare which ain't cheap however you look at it...