Ultimately you have to answer that as yes. He made the route choice and he and three of his charges paid a heavy price.
Francis Dumas had 25 years service as a mountain guide. Resident of Montalbert he knew the Maurienne like the back of his hand with a very long experience of ski touring. Mr Dumas was leading a group of high school students specializing in sports, their future lay as ski instructors and guides; that requires experience on the ground in a variety of conditions.
One can imagine the dilemma for a guide. If he doesn’t go out at risk 3 or even 4 he won’t earn a living. There are ski tours that can be done at all risk levels but it should still be remembered that risk 3 is Considerable, it is not an average risk but one where skier triggered avalanches are likely and requires careful route finding.
The avalanche bulletin mentioned a risk of slabs with weak layers from north-west to north-east but didn’t predict an avalanche of the scale of the one at Valmeinier. The police said the slab measured between 100-150cm and broke over a width of 270 meters running over 300 meters altitude and covering a considerable horizontal distance. In the police photos another slide has been triggered to the right of the group. This kind of slide is more consistent with a risk 4 and the bulletin didn’t predict such an avalanche as likely.
The slide was remotely triggered. The group was climbing a west facing slope when they were hit from above. The crown follows the whole length of a small summit, breaking on a convex rollover close to visible rocks.
The route choice of the col des Marches does not unreasonable but it is a reminder that you have to be careful of the slopes above. Ski touring groups are always vulnerable when climbing due to the difficulties of group spacing, escaping from the slide with climbing skins and the length of time they are exposed to risk.
Did they go out in poor visibility or did the cloud come down later? Poor visibility makes rescues complicated and also make route finding difficult. It is easy to stray onto slopes steeper than you think although this does not seem to be the case in this incident.