Local news coverage here:
Crash en Gironde : l'hélicoptère localisé dans la Dordogne avec le corps de l'enfant à l'intérieur - SudOuest.fr
According to some sources a previous owner of the estate also lost his life in a helicopter accident.
Sadly I have to agree with Wander's and ATN comments about notaires in France, they have a different role to their counterparts elsewhere - they act as more of a Tax Collector than an advisor vs. their UK counterparts and their scale of charges is absolutely eyewatering.