They made the stupidest of choices, a dangerous one, to pass on the right of a very narrow gravel shoulder, nearly lost control and almost ditched their vehicle in the process. This was between sixth, seventh or eighth line.
The proper thing to do is pass on the left when there is sufficient room (as all of the other motorists were doing) and giving a minimum of one meter (148, 6.1) while doing so.
Had they ended up in the ditch, it would have been their fault.