Whistleblower (The Office) fourth appearance on the show, after first appearing in "Sabre". Zach Woods made his ninth appearance on the show. While talking with his real estate agent on his cellphone, Dwight states that the office park is 1725 Slough Avenue. "Slough" is a reference to the UK edition of "The Office" which is set in Slough, United Kingdom. In its original American broadcast, "Whistleblower" was viewed by an estimated 6.60 million viewers with a 3.4 rating/10% share in the 18–49 demographic coming second in its timeslot after the season finale of "Grey's Anatomy", receiving the same rating as last week's episode,
Engineer's Office of the Former Pumping Station consisted the workshop and the fitters' quarters, became a hazardous goods store. The third building, which had consisted the overseers' quarters and the office, became a hawkers control office. In the pre-war and early post-war days Yunnan Lane, which was located by the side of the post office, became a place where professional letter writers set up their stalls. There were as many as 37 stalls. This traditional trade gradually disappeared with raising literacy. The post office ceased operation in 1967 with the opening of the nearby Kowloon Central Post Office. The vacated post office was then used as a