At the beginning Bertie is reading the Sporting Times Newspaper. As he is talking the paper is open on his lap and there is a clear logo of Sky TV visible.
When Bertie is "buried" on the beach, his chest is moving up and down under the sand. Obviously a very thin layer of sand is covering him.
When Bertie talks to his aunt on Westcombe seafront, during a brief shot in which Aunt Agatha tells Bertie to 'stand up straight' a TV aerial is visible on a roof.