Auditors are engaged to express an opinion on the quality of your financial statements. A typical positive audit opinion will say that your statements present your financial position “fairly, in all material respects.”
This isn’t the same as being free from error!
Straight from the CICA Handbook (Canadian Institute of Chartered Accountants): “An item of information, or an aggregate of items, is material if it is probable that its omission or misstatement would influence or change a decision.”
As part of their audit, your accountant makes a determination on what amount is material for your organization. They assess any errors they identify relative to this materiality threshold. Thus, they may pass small errors without making corrections.
This would be a good point to discuss with your auditor, so that you understand their process around addressing any bookkeeping errors they find.