Did you guys watch Talking Dead last night ? They explained that last zombie kill. I didn't catch it until I heard the explanation. The zombie had eaten Ricks wife's dead body and thus the swollen belly. The bullet he found was the one Rick's son shot her with. There was hair in the zombie's mouth. The blood on the floor was where the zombie drug the body. Too much for mind to grasp at the time but they were talking about how they were surprised they got away with so much gore on this particular episode. Split zombie heads and one zombie chopped in half spectacularly and such.