The "Ausfahrt" sign the staff hangs inside the department to mark the exit might have had its intended comic effect, but the sign itself was incorrect for that use. In German, "ausfahrt" denotes a vehicular exit such as that on a highway or in a parking lot or garage. It literally translates into English as "drive out." The proper sign to have placed inside the store, intended to show people how to get out, would have been "Ausgang."
Mr. Lucas and Mr. Humphries clink their beer mugs together and both are supposed to shatter, but only Mr. Lucas' does. Mr. Humphries then breaks his mug with his hand to complete the joke.
Miss Brahms, Mrs Slocombe and Mr Mash can all be seen waiting for their cue to start acting as the episode opens (with Mash backing quickly out of shot to 'arrive' soon after).