"The speed and manner of driving of the following vehicles..."

Well the French enquiry (held shortly after the accident and ten years before the UK inquest, by the way) found that the paparazzi motor bikes were left well behind by the sudden acceleration of the Mercedes before it entered the tunnel, and that there was the strong probability that none of them were even in sight of the car as it crashed. It's hard to see how they could have had much to do with the actual crash. Just me searching for a bit of neutrality here...