the only way it is the baby-sitter's fault is if the lighter was hers... and i'm guessing it wasn't.
the fault here is with the kid obviously, because he KNEW that what he was doing was wrong. but since he is 5, an insurance company needs to find someone else to blame. i can't blame the baby-sitter based on the evidence given, because at 5, you don't get 100% constant supervision.... you just don't. .... so for me, it (blame) is with whoever left a fucking lighter lying around. totally irresponsible.