One interesting "hack" I would see clients do regularly as owner/employees, they would minimize their own salary to avoid payroll taxes, maximizing their distributions (distributions are not subject to payroll taxes). Unfortunately for them the IRS accounts for this hack, and if an IRS audit finds the salary isn't reasonable then those amounts will be subject to payroll, social security, medicare, potentially higher income tax, and moving forward affordable care act taxes plus penalties and interest. I personally hate this because there is no bright line rule as to what a reasonable salary is subjecting all business owners to the mercy of the IRS.
I am surprised this would happen to a YC company, not that YC is in anyway responsible, but I figured YC would be in a position to offer various business services (payroll, legal, tax, insurance, ect...) at extremely low cost. For example, I personally solicited YC and offered to provide Delaware incorporation/registered agent/annual compliance services to any YC companies at a discount which without the discount is already cheaper than legalzoom.