Davidson was in the prototype, the blue car, the ferrari was in a different class completely and also a lot slower.
It would appear that the driver of the Ferrari wsn't paying attention to what was going on around him,and was being passed by a much faster car and just turned into him.
This is one of the problems with Le Mans, there are a number of different classes of cars in the race so drivers have to be very aware of what is happening out there