Here i try to understand the basis of reasoning from the judge on why the judge decided that unfortunate driver is guilty
Several key point i want to highlighted from the report i read

"... makhamah bicara terkhilaf apabila menerima pembelaan Responden yang tidak mengetahui adanya aktiviti basikal lajak pada malam kejadian sebagai alasan untuk memandu keretanya secara merbahaya sehingga mengorbankan mangsa yang dinyatakan dalam pertuduhan. Responden seharusnya  memandu kereta dengan lebih berhati - hati dan bukannya memandu dengan laju sehingga menyebabkan kemalangan tersebut."

"...Responden yang memandu keretanya secara merbahaya mengambil kira keadaan jalan yang berselekohj dan berbukit sedikit"

In my personal opinon, i think what the judge trying to highlight, as a good driver, we must anticipate any possible danger . So whenever we encounter a location that has potential danger like reduce our visibility, down the hill, crowded place, and so we must able to take necessary step to reduce the risk.
For example if we goes into school area, we must reduce our car speed, in anticipating possible danger that kid will run across the road from no where. We cant just say, eh aku tak nampak ada budak lari" 

A dangerous driving will be like, even u know u are in school area, u continue to speed and somehow hit a kid. This is what considered a dangerous driving. Because u fail to anticipate n do what necessary. Same thinglah if  u drive during raining too

In this case, obviously the driver not only she was approaching a dangerous location. She goes down hill and approaching the corner and its dark. A good driver usually able to anticipate the risk of danger n reduce the speed,. Unfortunately, in this case, there is no preventive measure taken during this risk location. For this the judge said " Responden seharusnya  memandu kereta dengan lebih berhati - hati dan bukannya memandu dengan laju sehingga menyebabkan kemalangan tersebut. " (esp in the hilly area, at the corner and dark location)
The presence of the boys on the road is also wrong. But does it change anything if we replace the boys with ordinarly motorcycle, ordinary pedestrian, or romobongan orang? or TNB replace bulp There is no law saying that these people cant be presence on the road or the corner of highway. So a responsible driver must always able to anticipate dangerous location n do what is necessary , whatever preventive measure to prevent accident. This is in my personal opinion, the basis of the judge reasoning on the case (or course tambah dengan statement inconsistentcies like tiba2 ada new version of another car hit the kid)