In a recent conference Dominique Letang, guide, member of the French rescue services and head of the French Snow and Avalanche Research Association replied to the question about the use of the avalanche bulletin in legal disputes and prosecutions. His reply is interesting
Using the Avalanche Bulletin is like using a road atlas to plan the route you will take in the mountains: it is not completely useless but it is not the best tool for the job. In any event it could actually be the reason you get lost!
This opinion is based on the fact that the avalanche bulletin is relatively imprecise because it is based on a region rather than on a specific location and it is not nuanced enough because the Europe Avalanche Risk scale has only 5 levels, is empirical because it is based on the knowledge of a forecaster et sometime erroneous if the meteorological conditions don’t actually occur, for example if the local conditions are widely different from the general conditions.
Apart from that, it is clear that we cannot evaluate the risk at the scene of an avalanche incident from a bulletin that did not take into account the particular conditions at that spot, not the avalanches that have occurred in the recent past.
The law should never take the avalanche bulletin as a major piece of evidence except in very particular instances. It should never be a central element in a judgment either for the defense or prosecution. It is fundamental that that should be officially acknowledged, in the first instance by the organization responsible for the bulletin, in order to let the forecasters work without undue influence and in particular by decision makers and advisors so that they do not abandon their responsibilities.
That said, I encourage everyone to consult the avalanche bulletin because it is a good tool for the majority of backcountry travelers in the majority of situations.
I think Dominique is particularly concerned about the global risk level being used as a decision making tool. Risk 3 and we close the off piste (as has happened at Montgenevre and la Grave) or risk 4 and the town hall evacuates buildings under the threat of not having civil liability coverage.