Here is an extract from a preliminary AAIB release.
"The aircraft was taking part in an air display at Shoreham Airport during which it conducted a manoeuvre with both a vertical and rolling component, at the apex of which it was inverted. Following the subsequent descent, the aircraft did not achieve level flight before it struck the westbound carriageway of the A27.
Unless some kind of unforeseen event, such as mechanical or other technical malfunction occurred at a critical moment during this sequence, it remained the pilot`s sole responsibility to manage the effective flight path and energy state of the aircraft.
Once technical malfunction is ruled out, there will be little else but the reason(s) for a failure to manage effective flight path and energy management and monitoring by the pilot. Therein will lie the thorny issues of the whole spectrum of innocent error and mistake to neglect to recklessness.