Here's some new information given by a French newspaper (Le Parisien) in today's edition: the maximum weight the gangway could handle was 3 tons. While the 48 people being on the gangway on that fatal day amounted to 3.5 tons. Overweight is no question.
Also, the Chantiers de l'Atlantique passed an order on Nov 8th (one week before the accident) for a sign that was supposed to indicate that the gangway itself was not for public use, however the sign was never delivered on time. The gangway itself was commissioned only to serve for cargo handling. The order requested that the gangway handles a maximum weight of 1.5 tons.
Additionnaly, it seems that the 48 people stationned on the gangway were waiting for an ID Check, that was supposed to be handled on shore of course. Only it didn't.
It seems also, according to a testimony, that the collapsed gangway was the only one available that day (while the visit itself had been organized long before, so time was not an issue in finding an appropriate gangway).
All of these elements, according to the newspaper, come directly from the preliminary investigation led by the local court of justice.