On the 17 may 2011 a Cabri in Germany got an full engine failure on comparable conditions during an exercise autorotation. The pilot was able to land without further damage.
According to the german accident board they tested while investigation
3 different carburetors and on each trial the engine failed during low g conditions.
Guimbal assured an isolated problem on the affected german helicopter s/n 1016.
without further impact on the other ships.
Seems to me not a question of recommandations Mr. Guimbal!