At 00:50:10, the dad has gore and blood smeared all over his shirt after escaping the infected. As he reloads his gun, the gore turns into two small spatters and then back again to the gore between shots.
When Max is driving with the woman he rescued from the van, he takes out his pistol and checks the magazine. The pistol is a Beretta 92F. When he arrives at the police station, his pistol has changed to a Glock.
When Brooke's mom gets the shotgun, the shotgun shells have no primers, indicating that they are dummy rounds.
When the deputy enters the Police station to shoot the infected in the cells you can see behind him in the window several cars driving past despite the town supposedly deserted or dead.