That's a non issue. At the end of the interview, you go out in the main room, and will go and see their finance person to ask her to reimburse you, no question

That's a non issue. At the end of the interview, you go out in the main room, and will go and see their finance person to ask her to reimburse you, no question asked (bring a copy of your tickets in case she asks to see them, but I don't remember she did). You will get the answer later, and decision making is independent.