Adam Hosein has recently proposed that a sufficient degree of intervening agency between a person’s contribution to an unjust lethal threat and the posing of that threat can exempt the contributor from liability to defensive killing. Hosein suggests that this will exempt most civilians from liability to lethal defence even if they contribute to unjust killings. I argue that intervening agency does not bear on a person’s responsibility for a threat, and does not exempt her from liability to defensive killing.