TAO office outside the Tambon?

So far I believed that the office of the local administrations is always located within the area they administer. But when I was working through the TAO of Tak province, and tried to add the locations of the offices into the XML as well, the TAO Ban Na came out oddly. When I first found a placemark labeled with it in Longdo map, I already wondered why it is located so close to the district office and thus within Sam Ngao subdistrict, so I put the location into the XML only as a comment. Anyway, there's no building directly at the mark, even for the district office I had to guess a bit as none of the buildings looked like the normal large district office buildings.

Now I looked into them again, I tried again to verify the location, but none of the other sources gave anything - Wikimapia only marks one school around there. The website of the TAO Ban Na was offline, but still in the Google cache, and there I found the address - องค์การบริหารส่วนตำบลบ้านนา (ที่ว่าการอำเภอสามเงาหลังเก่า) ม.5 ต.สามเงา อ.สามเงา จ.ตาก (TAO Ban Na, old district office Sam Ngao, Mu 5, Sam Ngao subdistrict, Sam Ngao district, Tak province). Now there are of course TAO which cover more than one subdistrict, but this is not the case here - Ban Na only covers the subdistrict Ban Na, whereas Sam Ngao subdistrict is shared between TAO Sam Ngao and the Sam Ngao subdistrict municipality.

Once I found with Wikimapia that there is a new district office located close to the Bhumipol dam airport, the old district office as the location of the TAO Ban Na became easy to place. But still, it is located within the boundaries of the municipality and thus well outside the area which is governed from there. Finally, I even succeeded to locate the municipality office, close to the new district office, only the location for the TAO Sam Ngao I failed to find.

Now I am just wondering why this TAO is such a special case. One reason could be of course the topography on Ban Na subdistrict, which covers only the mountainous areas around the Bhumipol lake and therefore hardly any bigger settlement with the infrastructure for an office building. The whole subdistrict has just a population of 2145. And I am of course wondering if this is the only such case, or if there are any other offices located outside their area of responsibility.