A tie down is typically a cube of a couple of feet, which will usually kill any third party whom it hits in freefall. Statistically it is likely to fall randomly from an aircraft into an uncongested area. We can be reasonably certain that the pilot did not deliberately flout the law but made a mistake. He paid £1700 in fines and costs.
A motor car is typically a cuboid of several hundred cubic feet, which will often if not usually kill any third party whom it hits at typical speed. Statistically it is more likely to encounter such a third party as such third parties tend to be more densely populated than average close to roads. A driver who deliberately flouts the speed limit can expect a £30 fine.