...I'm also not fond of the word "fault", but that's another issue.
Here's from a Thesaurus ... I vote for boob
fault
noun
1. responsibility, liability, guilt, accountability, culpability It was all my fault we quarrelled.
2. mistake, slip, error, offence, blunder, lapse, negligence, omission,
boob (Brit. slang), oversight, slip-up, indiscretion, inaccuracy, howler (informal), glitch (informal), error of judgment, boo-boo (informal) It was a genuine fault.
3. failing, lack, weakness, defect, deficiency, flaw, drawback, shortcoming, snag, blemish, imperfection, Achilles heel, weak point, infirmity, demerit His manners always made her blind to his faults.
failing credit, strength, asset, merit, attribute, virtue, goodness, perfection
4. misdeed, failing, wrong, offence, sin, lapse, misconduct, wrongdoing, trespass, frailty, misdemeanour, delinquency, transgression, peccadillo Hypocrisy is one fault of which he cannot be accused.