Possible Clues:

• Things will always go wrong with its principles
• 'The principle that says that anything that can go wrong, will go wrong (4,3)'
• Turf hunk out of Britain with tendency for trouble
• If something can go wrong, it will!
• Saying about overdoses with line: 'If it can go wrong it will'
• Oswald's assassinated — if it can go wrong it will?
• Pessimistic canon's portion of ground cabbage salad
• Sold out through saying: 'If it can go wrong, it will'
• Maxim's grass salad
• Oswald's unlucky formulation