At the funeral, the reverend says "we're here to commit the ashes of our dear brother uncle Fred" yet, he comes back as a zombie which would be impossible if he was cremated.
James at his grandfather's (Uncle Fred) funeral, when talking to his dad he refers to Cape Canaveral as Cape Kennedy, but it had not been called that in decades. The name was changed back to Cape Canaveral and The Kennedy Space Center is located there.