Mm.. I don't want to sound like a troll, and definitely not to give my support to TFA, but the opponent in your rhetorical argument actually brings up a good point. "But you could be wrong" should always be considered. The current financial crisis came about, in part, because of not enough people with a lot of money thought (or cared...) to ask "but what if I'm/we're/they're wrong?".
Of course I don't mean that the LHC should shut down or any number of risky scientific endeavors should not be undertaken; the benefits almost certainly outweigh the risks. And I certainly have no idea whether the calculations done to show the LHC is safe or unsafe were rigorously done. I'm just pointing out that, hey, doubt and questioning have their place in rigorous science and shouldn't always be brushed away as fear and ignorance by the masses. Even scientists can get caught up in their own enthusiasm for a project.
You don't have to know how the computer works, just how to work the computer.