An opinion is not guarantee of an outcome, but rather a statement of professional judgement. The auditor cannot obtain absolute assurance that financial statements are free form material misstatement because of the inherent limitations of an audit. These are caused by a number of factor. For example, many financial statement items involve subjective decisions or a degree of uncertainly. Consequently, such items are subject to an inherent level of uncertainty which cannot be eliminated by the application of auditing procedures.