Putting a clause in the contract stipulating that he isn't an employee doesn't mean anything, at least in the state of New York [1].

I should know, my previous employer got me to sign such a contract, but the state determined I was indeed an employee after I was unjustly fired, and now I can legally collect unemployment.

1. https://labor.ny.gov/ui/claimantinfo/ui%20and%20independent%...