Possible Clues:

• This is how daughter prepared cabbage: why does it all go wrong?
• 'The principle that says that anything that can go wrong will go wrong (4,3)'
• That which suggests that, if something can go wrong, it will!
• Why a dropped slice of bread will always land butter side down, perhaps
• Theory that a dropped slice of bread will always land butter side down, for example
• By precisely which you'd get earth touching salad
• Rule that if anything can go wrong it will
• If it can go wrong, it will
• Pessimistic theory was sold controversially
• What can go wrong will go wrong