Hogan's men including LeBeau give Hogan their watches to prepare the bait against the Gestapo black marketeer. Later at the Hofbrau, soon after Hogan shows the watches on his wrist, LeBeau is seen checking his watch before turning on the Hofbrau's side door outdoor light. Update: LeBeau is sitting right behind Hogan as Hogan makes his blackmail play on Kiegel. Hogan leaves the Hofbrau alone. LeBeau does eventually go to the back of the Hofbrau to turn the light on. As Hogan would have had to pass LeBeau on the way out of the Hofbrau, it is entirely possible (and probable) that Hogan would have dropped LeBeau's watch off to him as he passed by.
Colonel Hogan becomes angry when he learns that a Gestapo agent has visited the camp and no one told him. Kinchloe tells him it's because he was busy listening to the World Series. In the 1940s, the World Series was played in late September/early October. In the Hogan's Heroes universe, it is perpetually winter, well after the World Series would have been played.
When the black marketeers attempt to smuggle their goods out of the back of the restaurant, a nearby light is turned on. This clearly illuminates their activities, prompting Major Kiegel to shoot out the light. He fires two shots, with the second one hitting the light; however, the pistol clearly jams after the first shot. Kiegel doesn't actually fire a second shot though the sound of one is heard. Update: Note that there is a muzzle flash on the first shot, but not the second - which confirms that only one shot was actually fired, with the sound of the second shot dubbed in.
When Kiegel shoots out the light above the door where they are loading the truck, the first shot misses the light, but it creates a cloud of dust at the top of the doorway. Before the shot, the squib that causes the dust cloud can be seen as a small white patch at the top left of the door frame.
The plastic protractor that Hogan is shown using, and the US dollar bills shown on the table in front of LeBeau during the card game are not accurate to the period.