It seems that the wood is only held in position by the weight of the vehicle. This is completely unsatisfactory in an aircraft. If the wood moves, the restraint becomes slack enough for sudden forces to allow vehicle momentum prior to restrain action. Restraint systems should ensure zero movement of all components.
If the wood was individually restrained to the aircraft or to the vehicle, there would be less chance for the restraint system to become slack.
During my C130A days I took great responsibility to check load restraint, arriving at the aircraft up to 60 minutes before the loadmaster and rest of my crew. I always assumed there would be a difficult to see problem, but there never was. I would not have accepted wood support that itself was not restrained.
It is starting to look like dunnage movement was the initial problem. They probably do not really want to explore this possibility because it is an approved restraint system.