Perhaps they don't know (yet?) what exactly went wrong? The car was heavily destroyed, I am surprised they got any logs retrieved from the car at all. They might be able to reconstruct more information about the accident, but unless they have a complete log including video (unlikely), it will take time to reconstruct. As there is an ongoing investigation about the accident, it is understandable, that they are not making any statements beyond anything they can prove without a doubt at the current point of time.