Based on Hussein Zaidi's book Black Friday is already going through a lot of controversies before its due release.
Like for instance, there is a scene in the film where Pavan Malhotra who plays Tiger Memon talks to his aides about destabilizing India for which Kashyap shot two separate scenes. The director very much wanted the two names (Advani and Thackeray) in the film.
So shooting two scenes did made sense, if there would be a problem they could switch the scenes.