I've picked up many a trailer in different ports and never knew what was in them till they reached their final destination, paper work can say one thing but the cargo may be different, if i was to pick up a container without a seal id check the paperwork to see if it was sent out that way, if not i wouldn't leave the port / haulage yard/ or whatever storage place it was in without getting the proper documentation signed to say unsealed by whoever was in charge.
But that was many moons ago ken, its very easy to blame the driver pulling the trailer in this case and i for one wouldn't blame him.
The headlines of driver arrested on suspicion of mass murder is a discrace, the poor man will never be the same again mentality and all the keyboard warriors and the media out there calling him all kinda names is wrong in my opinion.