D777, yes I believe you are mistaken. I can tell you for a fact that in the company I work for, I have the pleasure of flying most days with people from just about most corners of the world. Let's compare logbooks, mine reads like a guest list at the United Nations.
I don't know what it says in the BA black book of recruitment, but I doubt sincerely if there's any sort of policy to be judenfrei or exclude Eastern Europeans. Aside from being illegal, it's not actually the sort of thing they care about. By and large, corporate UK left that behind many years ago. As long as you're legal to live & work in the UK, meet the aptitude requirements they set and have the correct qualifications I'm sure they'd probably not even think to ask which racially-obsessed part of Eastern Europe one might be from.
Whilst I respect your opinion that an airline ought to take responsibility for employing pilots from its own country, I disagree. An unemployment agency has that responsibility. The airline is a business, its responsibility is to do the best by itself. If we take your argument to its logical conclusion, a a citizen of whatever country you should take responsibility for buying products made in that country. Enjoy your Serbian computer, your Lithuanian car or your Polish mobile phone won't you?