You have certain taxpayer rights to protect your interests. Most importantly, you have the right to professional representation. Hiring a professional is no admission of guilt – its simply a sound business practice. Most seasoned IRS examiners would prefer to deal with a licensed professional anyway – one that understands your reporting obligations and will not get emotional when errors are found.
The IRS tax examiner is simply doing his job. His job is to protect the government’s interests and collect additional taxes from you that you may owe. Tax examiners are skilled and experience in their techniques and will strive to collect information that can be used against you.