@thrasher1 Page 23 of the rulebook, Liberating Zombie Controlled Territories.
SMO, I interpreted this rule wrongly. For me personally getting the 1 infantry bonus only when getting rid of all Zs in an area made more sense.
But to you and others: thanks for clarifying issues like these. Let’s hope there is an official FAQ soon. You are probably one of the persons who will compile this FAQ 🙂