This article make it sounds as though the truck was passing a car when the collision occurred. Question is whether or not that area is a passing zone or not? If it was a no passing zone then, IMO, the fault lies mainly with the truck passing the car. If this was a passing zone then the driver of the truck would have a legitimate excuse of not being able to see the bikes because they were reportedly operating without headlights. Either way, based on my experience of driving on SXM, traffic laws are simply a suggestion.