Believe me, that happens. When I have rented cars in England, New Zealand, and Australia, they figured I would get it without too much trouble. This is related to the topic, because it was admittedly more trouble for me that one might think. I went into the wrong lane on turns several times. Learning to shift gears with my left hand and dealing with all other controls on the "wrong" side of the car was interesting, to say the least--on my first day in New Zealand, I kept turning on the windshield wipers whenever I wanted to signal a turn. In each case, I did catch on pretty quickly. The lesson learned is that when renting a car that must be driven on the "wrong" side of the road, it is a good idea to drive in a safe area while getting the hang of it.It is somewhat apples to oranges but what if all their experience was driving on the "wrong" side of the road.
Sounds kind of like a recent diving experience requirement, doesn't it?