...the article addressed them (if you read between the lines).
The car was modified for disabled use and was apparently all-electronic control, including start/stop, gear, power, and brake. "Braking" accelerated the car from 100 km/hr to 200 km/hr. As I imagine the driver was familiar with the car, he may have tried using the other electronic controls--although after "braking" doubled his speed I imagine he was reluctant to do so for fear of what would actually happen. This is further supported by a Renault tech being in contact with the police who couldn't suggest anything more for the driver to do besides wait for fuel exhaustion.