I HIGHLY doubt a customer is obligated to provide anything relating to the contract with the driver. The contract is between the customer and the trucking company.
The driver’s contract is with the trucking company. If he has any grievance, he would need to take that up directly (via a competent Attorney if he has any sense) with the trucking company.
Of course, this is all moot because he chose to come here to complain instead (presumably) of pursuing legal action.