I suspect those five were going on much more than the word of one person. I don't have personal knowledge of the community in question, but these fishing villages in the Maritimes are not places where people routinely burn out their neighbours; they also tend to be places in which people have a pretty good idea about what's going in what house. This would have been a case in which the community was extremely frustrated with an unacceptable situation that had gone on for some time and showed no sign of abating, so they did something about it.

Also, testimony in the trial suggested that police officers had confirmed or agreed in private conversation with the accused that there was drug-dealing going on out of the house in question. This obviously would not have been the case in the incident involving your daughter.