What makes you think they didn't check the switches beforehand? Do you have inside knowledge that we don't have? I've check my lights before I put them up and they lit fine. Put them on the tree, and...no light. Like the other poster said...it happens. Most folks don't get all bent out of shape about it because they know it happens to just about everyone sooner or later.
Here's a solution. Next year....don't go. That'll teach 'em. I'm sure it will shut down because you're not there.
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