'The problem for Michael was not the hit, but the mounting of the Go-Pro camera that he had on his helmet that injured his brain,' said Moncet.
Moncet confirmed that Schumacher was still 'fighting' at his Swiss mansion, where he is being cared for in a purpose-built medical suite.
The seven times world champion returned to his home with his wife and children two months ago after being discharged from a rehabilitation clinic in Lausanne, Switzerland.
Schumacher spent time in the rehab clinic after coming out of his medically-induced coma following the accident, which left him with catastrophic brain injuries.
Updates on his condition have been few and far between. After he was moved home, Schumacher's manager Sabine Kehm said there was a 'long and difficult' road ahead.
Former Ferrari boss Jean Todt visited Schumacher last month, saying: 'What's important is that he lives and that his family is with him. We really believe that things will get better. He needs time and to be left alone.
'In the past weeks and months, he has made progress in relation to the severity of his injury,' said Todt, now president of the International Automobile Federation.
'But a long and hard road is in front of him. Hopefully things will improve. His family is close to him. He needs time and peace.'
Schumacher is being cared for by a team of 15 experts at his home. It is understood he remains immobile and unable to speak.
His care is estimated to be costing his family 100,000 pounds per month.
At the end of the year his father Rolf is moving from his home in Germany into a specially constructed residence built for him in the grounds of the 35 million pound Schumacher mansion at Gland, on the shores of Lake Geneva.
Mick has been tipped to follow in his father's footsteps in his own motorsport career.
The 15-year-old finished runner-up at the world championships in France last month, before coming second again in the German junior kart championships last week.
Having raced under the surname of Betsch, his mother Corinna's maiden name, Mick Schumacher adopted the name Mick Jnr this season.
Last month he spoke of his intention to pursue a career in the sport, saying that it was 'only the beginning'.
- Daily Mail