At the start of the show it calls the Scharnhorst a "battle cruiser". Although commonly described as such in much of contemporary naval histories, the Scharnhorst was not a battle cruiser. It was classified by the Kriegsmarine as a "light battleship."
During the historical background the German panzerschiffe is equated to the "pocket battleship." While pocket battleships was a term used for this class of ships, it was a derogatory reference created by the British. The Germans would never have used this term. The proper translation of panzerschiffe is "armored ship." This was used as the Kriegsmarine did not feel that there was an existing term to define the Deutschland class. Later, the surviving ships would be reclassified as heavy cruisers.
At 11:48, during the description of the attack on HMS Glorious, the narrator incorrectly refers to the Scharnhorst as a "pocket battleship." The term "pocket battleship" was a British reference to the German Deutschland class of cruisers. The Scharnhorst was never referenced as such.