independant contractor vs. employee

[Publius]

Employee for payroll withholding purposes and employee for WC are cheese and chalk. WC is a state issue, for one; IC/employee an IRS one. They are not necessarily mutually inclusive.

IC status relieves the customer of mandatory payroll tax withholding obligations--they don't have to crate a new subsidiary account for the IC. If you're already an employee, that's a non-issue and one that school districts don't want to argue: "Why didn't you withhold based on ALL his compensation?" Hence, your friend's predicament.

Officiating is (probably) not part of the teacher's official duties; he can decline any assignment working for his employer's teams without recourse. He can say, "I'm not working our school teams' games", but (probably) can't say, "I'm not teaching third-period English."

The variance in state WC laws precludes a definitive answer here. In my state, he'd have a weak case for a WC claim based on an injury sustained while officiating. He wasn't performing his "official" duties (pun intended), and while he is being compensated by the school, he isn't "at work."

It may be different in your state. There is no one dispositive rule that does or does not make one an IC, and simply having taxes deducted from your check doesn't automatically make one an employee.