Free Traffic Legal Advice

Unusual topic. We are charitable group in EY helping Ukraine -one of the activities is purchasing pickup trucks for military and driving them to Ukraine. As our drivers often foreign without UK licence  and vehicle exported from the UK soon after purchase EU cover insurance is a must have (as asked on the border). We use valid EU broker to get insured with representation in the UK as partner company -never had a problem till last week. Our this time foreign driver but with UK licence was taking a vehicle to the ferry crossing and was stopped by police implying insurance certificate is not valid cos not issued in GB and not on driver name. Any explanations has not satisfied the officer so they issued 300£ fine and 6 points on driving licence -admitted though he doesn't understand the insurance certificate presented (cos not in English) and need clarification how it works. They also stayed till we get temp cover sorted (which is not valid in EU by the way). There is no any information for appeal or contact details or reference provided except name of Police dep. What are steps to prove the vehicle was insured please and do we need to appeal going through court? We obtained English version of certificate from the broker now. Thank you.