WHAT exactly is Arun Nehrus involvement in the Bofors kickbacks? No one will confirm, but top CBI sources say that years after his role in the deal has been debated, it seems that the hens are finally coming home to roost. Last fort-night, Arun Nehru was served summons: not an easy task if you have left for personal work to the US on the same day CBI chief Joginder Singh was returning with the 500 pages of Bofors dynamite from Switzerland.