I'm almost certain that all insurance companies ask 'have you ever had a policy cancelled or declined' so he will have to answer that question.
Also ALL car insurance details are registered on the MIB (Motor Insurance Bureau ) database, so as soon as he applies for a new policy with any company that company will have all his details. Do not try saying he has never been insured as that will flag up on the database as untrue and lead to automatic refusal.
Also he will have to explain why he is shown as being previously insured but does not have a NCB!
Sorry, but he is going to have to face the consequences of his poor driving!