There is new (inofficial) information regarding Bianchi's accident. German automotive mag Auto Motor und Sport reports that the g sensor measured a peak of 92g for the crash. These sensors are mandatory and are integrated into each driver's earplugs. Thus, this is the actual g that the head suffers. According to Bianchi's father, the doctors are surprised that Bianchi survived this amount of force at all.
Additionally, the German mag AutoBild claims to have information on the details of the crash. They say that his team, Marussia, asked Bianchi not to slow down despite the double yellow flags to make sure that he won't lose a position to Ericsson. The latter was on fresh rain tires and approximately 1s faster on the previous lap than Bianchi on his 15 lap old intermediates. This statement seems to also have been recorded.
The rule for double yellows is that each driver must drive so slowly that he is able to do a full stop at any time if necessary. Given the speed that Bianchi crashed with, he must have been going much faster, so this does unfortunately make good sense.