Factual error: Bobby's shotgun hit blasts a hole through the head of the first zombie entering the store, but the zombie directly behind it, as well as the barricade, are unscathed. The shells can hardly penetrate this much, wide and clean through the head and then disappear with no trace. (01:35:05)
Factual error: There is a modern digital electric meter in the record store - not what it would look like in the era of the movie.
Factual error: Drinking a juice box in 1977. They didn't appear in the US until 1980.