I don't think she'll need a good defence layer (although legal council will probably be given of course)
She's facing a €1500 fine but tbh I doubt it'll come to that. (maybe they come to some sort of settlement with an official apology or something like that)
It is very difficult to build a case around situations like this.
The strongest point is that she left the scene of the accident before authorities arrived.
I read in another article that if a rider made a personal complaint she could face €15000 or 1 year jail max per article 222-20 du code pénal:
https://www.legifrance.gouv.fr/codes...I000024042640/
But I think that has no chance because the case lacks intent which is a requirement.
If a real lawsuit would be held, the strongest points for the woman would be:
1. the tour organizers are aware that incidents with fans happen, therefore they shield large parts of the track with fences. If they want to eliminate the possibility of incidents with fans, they should fence off the entire track or not allow fans to stand next to the road.
2. the tour organizers allow specators to have/show signs and stand next to the road
3. the woman had no intent to cause the crash. It was an accident caused by a momentairy lapse of awareness
4. the riders drove into her.
In the end this is foremost sad. Sad for the riders that got hurt in the crash, sad that fans are there apparently more for seeking their own attention than to enjoy the sport. But that last aspect has been known for many years now and many similar accidents have taken place in the past.
In the end the only thing the tour organizers can do is concentrate on fan awareness (and in this case, that woman could have been seriously injured too), more stewards along the track, maybe more motorcyclesupport in front of the peleton (deadly crashes between supporting motorcycles and fans also have happened in the past) and maybe even more fences alongside the track.
I'm not defending the woman who caused the crash, but sadly this is a known issue the organizers have to deal with. People are just plain stupid. It's a fact of life.