I'd like to clarify the issue. Personally, I think that the CPA in question in the article is an idiot for a number for reasons. (1) He's an accountant so he should've known that playing this game with the IRS as a CPA is begging the IRS to slam you. (2) Litigating a losing position like this so publicly is going to kill your reputation and put you on the IRS' top 10 favs list for life.
This is a very clear issue actually and I'm not sure why there is so much confusion and I'd disagree with calling this tax plan a "trick."
It is a legally sound tax plan with a justified theory. You are allowed to exempt a portion of your income from payroll taxes because they are "corporation distributions." Corporate distributions or dividends are not taxed as earned income because they are considered passive investment income. An S-Corp is a corporation that abides under a specific subset of rules within the IRC's Corporation Regulations, thus it is for all legal purposes a regular corporation with certain special rules.
A reasonable salary is a fairly straight forward question. The IRS won't nitpick with you on silly numbers as long as you fit within the range. Obviously, for every position there is a high and low salary range, so as long as you fit within that range the IRS will leave you alone.
The CPA is an idiot because he underpaid himself below market rates to the point where he couldn't justify his position under any reasonable defense.
If you were developer, then you would be paid anywhere from 40k to 250k+ depending on your company, position and experience. Thus, you could potentially pay yourself 40k in reasonable salaries if you owned an S-Corp and take the rest as a dividend. As long as you are able to provide "comps or comparable salaries" to positions with equitable responsibilities and experience in your local region.
The important thing to remember is to be reasonable.
I'm a full-time tax accountant, so this is coming from years of experience in the field with direct contact with auditors from the federal and state levels. They won't come knocking unless you were being a greedy idiot because like the article states it's expensive for the government to audit someone, so when they do audit you it has to be a profitable venture (thus, they usually audit the sure-thing losers).