Just because a taxpayer did everything "by the book" doesn't mean that an audit will be quick and painless. Or cheap. IRS agents get things wrong (or disagree with a tax strategy / application of tax law) all the time, and it can be a huge headache. I hear it all the time in my line of work. The IRS routinely misplaces documentation, tax returns, uses antiquated tech, undertrains staff, etc. It's not a system that is friendly to the everyday person/taxpayer.
For example, in one of my areas of specialty we routinely have to fax documentation to the IRS. Not a typo - fax. I help companies right proposed penalties in the hundreds of thousands and our response documentation sit on a stack of faxed papers in the IRS office in Ogden, Utah. The IRS has been working in this particular tax area for almost 10 years now and has not implemented anything better than a fax system. We've even had cases where one IRS office has *faxed* client documentation to another IRS office, but did it the wrong direction (landscape), so the receiving office sent a penalty notice to the taxpayer because it violated an IRS rule for proper formatting of returns. So the taxpayer gets hit with a penalty for something they didn't cause. This same group doesn't return voicemails either, so fixing the IRS's misstep isn't straightforward for those who don't know the background. They also don't communicate well between divisions and are understaffed. It's a racket.
I recommend against triggering IRS audits, if it's feasible, ethical, and within the law.