When this person is audited, it doesnt mean that anything was done incorrectly or maliciously, it simply means that your income was just large.
There are other things that can trigger an audit but these are just a few of the reasons that happen most often. Speak with a professional tax accountant who can help advise you on best practices and even offer their tax services for your particular situation.
One of the most important things you need to remember when filing taxes is to always keep your documentation. When you are filing taxes, this means keep the proof of your deductions, receipts and etc., and be honest.