I don't know about previous training methods, but I can say that night training into Barra, Bute and the North Isles is conducted nowadays before the relevant route certificates are issued.
Night ops. into 500m strips (with the exception of Bute with its PAPIs) are only conducted in Orkney and Shetland in the North Sea and it could be a hard surface or a grass surface depending on the wind, in most cases lit by battery lamps - however the orkney isles will soon have permanent runway lighting. It must be remembered that the North Isles are known like the back of each pilot's hand as daily scheduled services are flown in and out of the isles day VFR - up to 21 sectors in a day.
The night flying in the majority of the Western Isles (except Barra) is to airports with all their associated aids and facilities.
I certainly don't believe that the current Loganair operation is dangerous and wonder what a second pilot would do to remain awake on an Islander.
RIP Guy.