The video is very fascinating and a very close call for the news crew as well as resident that lost her home. But that said, the reason the news crew was at the site was an earlier traggic slide.
The landslide/debris flow was on the east side of Kootenay Lake. The lake is in a deep trench like valley with huge mountains rising above the lake shore. The fatalities (assumed at this point in time) were at home sites on what appears to be a elevated glacial terrace well above the stream where the debris flow descended. However, the volume of sediment appeared to have filled the ravine the creek was located in and came up over part of the terrace where homes were located. Difficult to know looking at Google Earth images, but this event may have been the kind with a potential recurrence interval in excess of what geologist often consider.
I have not often done geo hazard work in topography this extreme, but when I do I will mention the difficulty of predicting mountain scale events - the fact is very high steep mountains pose a risk.