"It certainly brought home the requirement to be very clear and explicit in your instructions and to then realise that someone else's interpretation of what you said can still be different to yours."
It can also drive home the point that sometimes you just can't win because you end up with a person who can't find their butt with both hands and a road map. Tell them to pick up the three-inch cylinder (the ONLY block in the bunch that matches the description), and they end up using the oblong brick. And they swear it's the cylinder, and when you ask what they call the cylinder, they answer "stick".
It's times like this when you wonder if "civilization" is overrated.