Originally Posted by
chil
1. The ticket was issued by BA as I stated in my original post (125xxx) .
Sorry I missed that in your op.
Originally Posted by
chil
3. My colleagues holding Russian passports traveled on similar itineraries and they didn't have to cross the Schengen border in "normal" German airports (FRA, MUC).
They are not "normal German airports", they are just the two largest airports in the country by far which handle a vast amount of transfer passengers (in both cases, the majority of their traffic) as does DUS, and are thus well equipped for connections. Same goes for ARN. Again, see my example above, if you have two flights going via CDG you will be able to transit airside, if you have two flights going via ORY, you won't be able to. If you consider CDG to be the "normal" airport, then you'll have to consider all other major French airports to be "abnormal". Logic dictates that in many ways, when you have a general case and one exception, then it is the exception which is not the norm and not the other way round.
I'm still not sure what you find irresponsible in BA's attitude there? Would you have wanted them to refuse to ticket this itinerary just in case some people forgot to check their transit requirements? Something else? What would you have wanted them to actually do??