A truck gets loaded by a forklift operator with the driver supervising. Once the loading is done a piece of paper is signed by the forklift operator - declaring that they have followed the driver’s load instructions. Meaning that as far as responsibility goes for the truck and its load, from that point on, its all on the driver.
Another example of CoR in action happens before a truck is even taken on the road; The driver needs to check that the truck is safe to operate by ticking things off and signing their name to it. The office participates to because staff, within reason, need to assess if the driver is fit to conduct their driving duties.