The longitude I've seen, 113° 52', is just east of the village. In fact, you can still find a boundary-marking obelisk where the line of longitude hits the coast.
The map you're referring to is, presumably, this one, a reproduction of the one annexed to the 1898 Convention that leased the New Territories. It seems that the cause of this is that you may have misapprehended aspects of what the map is displaying. The dotted line at 113° 52' E and the line at 22° 9' N which pivots to meet the land at Fan Lau delineate the limits of British territorial waters under the proposed lease, but there is no indication that Britain would not lease the entirety of Lantau. Quoting from the convention itself:
The area leased to Great Britain, as shown on the annexed map, includes the waters of Mirs Bay and Deep Bay, but it is agreed that Chinese vessels of war, whether neutral or otherwise, shall retain the right to use those waters.
The North and South Lantau Obelisks mark the points where the lines marking British territorial waters meet the land. However, they do not mark a boundary over land running between them.
That is not to say that the extension of British rule over the New Territories was uncontroversial, as is readily evident from the anti-British uprising by the rural communities in and around modern-day Yuen Long and Tai Po in 1899 known as the Six-Day War. However, none of the villages on Lantau participated.
