I just looked at a splendid new resource that shows the change in forest cover across the world between 2000 and 2012 (here). Below is a screenshot that zooms into part of the north coast of Borneo. Undisturbed forest is shown as green, forest that has been lost is red, and forest that has been gained is blue.
The big patch of red on the left (with just a bit of blue in there) is near Miri, in Sarawak. Overall, the findings confirm that Malaysia is one of the countries with the greatest loss of forest over the past 12 years.
This screenshot confirms that there has not been too much forest loss in Brunei, though there is a little around Muara and also some in the middle, presumably in Tutong District.
It is fascinating that you can easily make out the map of Brunei, especially its south-western border with Sarawak, by looking at the undisturbed green area. On the right, you can also make out Temburong fairly clearly, while there has been a little more forest loss in the Malaysian district of Limbang between the two parts of Brunei.