"I would have thought that was obvious. Prosecuting Lylou for not insuring a car after she's sent it to the scrapyard."
But they will say (and they could be right, who knows?) that they did not know she had sent it to the scrapyard. For the legislation to be effective it must contain such provisions as this (i.e. the responsibility lies with the Registered keeper to show they informed the DVLA). If it didn't it would be useless because anybody facing such an allegation can simply say "I sold it, guv, and I told you I did".
In fact this particular piece of legislation is more generous than most "strict liability" offences in that it does provide those facing allegations with an escape clause as I have described.