So he was not insured?
Ok. So what is your question?
He just produces an insurance certificate that covers him to drive this car on this date in accordance with the journey he was making and the case against him will be dropped.
There is no need to do anything else. If you send it in now then they will drop it.
That is, of course, always presuming that the insurance company do accept he was insured to drive. If so, they will give him a certificate.
Can I clarify anything for you?