I obviously get why folk do it - but in said example above....the offence was HIS, the punishment should have been made to be HIS too....yes, so that would have made life difficult for the family all round....so maybe he'd then think twice in the future and therefore not risk more points to risk his licence altogether!!!!

I'm sorry, having just reread my OP, I've realised that I had left out a rather important detail.

The letter came to the wife, as she was the owner of the car, but both she and her husband had driven the car down that road several times that day - for whatever reason - so they weren't sure who had been driving at the time of the incident.  They therefore asked for proof, but the photo they had back wasn't sufficiently clear to indicate who was in the driver's seat and, as it came 2 or 3 weeks after the event, they weren't actually sure about the various times they had been driving.  THAT is why they split the punishment.