Not necessarily - this is from the CAB website:
The driver may also have to report the accident to a police officer or at a police station, in person, as soon as practicable and in any case within 24 hours. This duty arises whenever the driver has not given their name and address at the scene of the accident, whether or not they were asked to do so.
If any personal injury is caused to another person, the driver must also produce a valid insurance certificate if asked to do so by a police officer, injured person, or anyone else directly or indirectly involved in the accident. If the insurance certificate is asked for, but not produced at the time, the accident must be reported to a police station as soon as practicable, or in any case within 24 hours, and the insurance certificate must be taken to a police station within seven days of the accident. However if the driver is asked at the time of the accident to produce insurance details and does so, there is no further obligation to report the accident to the police, as long as they have complied with the duties described above.
But copying a few hundred gig of files is less painful than a bad crash would be - if they'd hit a foot or two to the left ... (erm)