As far as I know , the haulier is responsible for all.
In our business , the minute the truck goes outside the main gate , he is fully responsible for load . And there has been occasions , where laod was damaged , and haulier had to claim from his insurance .
Ensure , haulier has all the necessary documents up-to date , including road haulage licence , hazardous goods carriers licence if applicable , safety statement , road worthiness certificate for both tractor and trailer and of course , his certificate of insurance etc