I think Lenzi was being so dishonest when he described his zombies as vampires. Ok technically vampires but they are so within zombie genre and away from vampire genre that he may as well have fessed up and said that yes this is a zombie film.
On a different note, the playful dog in the city seige scene. Me and my wife were discussing whether this could count as an error or not. I maintain that yes this is a goof where my wife pointed out that the zompires may not be a threat to the dog so he was entitled to be there, and that a zompire seige may be fun for the puppy.