Possible Clues:

• Blunder as I run away from tall creature
• Big mistake
• Foreman's right missed, proving a mistake
• Putting one's foot in one's mouth, e.g.
• Mistake made by public schoolboy once over further education
• Blunder made by foreman? Almost
• Something wrong with dwelling place ultimately
• Blunder as foreman, not reaching conclusion
• Old man nearly makes embarrassing error
• Error cutting short old man