You're right about the loopholes but wrong in assessing that some of them aren't being taken advantage of in a way that can be read as fraudulent.  Which is one reason he's being audited.  

You don't go to jail for incorrect filing except in extreme cases.  Usually filing incorrectly means you pay the addl money you owe along with any interest.  I'm an Accountant as well and I spent a great deal of time on the phone with the IRS every year handling tax problems for our clients. 

over 1000billable hours over time. You should already know that many people skirt the system & don't get caught right away.  Others get taken to the cleaners financially but they don't always get jail time.  Some make deals to pay a large portion of taxes owed while being able to avoid the entire sum.  There's so many different tax rules that a CPA needs to specialize in taxes or auditing alone to be considered an expert in the field. 

The issue isn't whether he pays its how will he change future tax laws