On the outset, I would say that the turnout of 68% is a big victory for BN despite the boycott call of all opposition parties. However, it will a mistake if the BN were to take the result as an indication of their support nationally.
First, the independent candidate hardly put up a fight. Second, he is an ethnic chinese standing in a Malay majority area. The electoral pattern in Malaysia in very race centric. Thirdly, some issues were not so visible for a semi-rural area such as Batu Talam where the main economic activity is agriculture.
If a by-election were to be held in a big city, the outcome may be quite different. The opposition parties would have scrambled to nominate a candidate.
The outcome of the election exposed the weakness of Malay opposition in the country.