* Why, when a human can't escape (like in the story about the island where the dying are left for the zombies), the zombie stops eating while there is still enough of the victim left to start walking, rather than consuming the victim completely. This is because zombies don't eat Solanum-infected flesh. The zombie stops once the virus has tainted its meal.
* One of the stories in the expanded Stories book details a man called Patrick [=McDonald=], who was bitten while camping before heading back to Los Angeles. You'd think it ends there, but no. Other stories take place in LA, and make references to a man who came out of the woods, attacking people as he went. Slowly, the puzzle pieces come together to make the full story. It turns out that Patrick made it to LA, and, in a three month reign of terror, caused the deaths of countless innocents and the subsequent arrests of anyone who killed the zombies to survive, in a police cover-up.