As someone who has worked in Asia and been to Laos, and had problems with ignorant customs authorities upon returning, I want to say:
Many customs officers have never left the UK and have almost never been to third world countries. They have no idea what life is like for the people there. Maybe if they lived in these places for a while, they wouldn't act the big shots they think they are.
Laos, in particular, is very, very underdeveloped (and corrupt, and communist). Many simple things you'dtake for granted in the UK, such as basic health care, exist only for people who can afford them. Even this basic health care is nowhere near the standards of developed countries. I have been given medicine in Asia that has been banned from developed countries becase it causes heart attacks.... This was medicine for someone who could pay, just imagine if you're in a prison... the lowest place you can be.
Paperwork in any country like Laos takes a lot of time and from experience, can depend on who's doing the paperwork. There is a lot of corruption and it's hard to get things done.
Many backpackers are so young, they have no idea what they're doing and are not streetwise. In Laos, there is a town with a beach and it is against the law to walk around the town in your bikini top for example. Well, if you're 18, you don't think of something like this getting you in trouble. Laos has a completely different culture and is so different from the life you have at home.
Many of you might not understand this, but I'm trying to explain a bit.