His license doesn't cover you. A real estate license authorizes the licensee to act for others in a transaction, and it attaches to that person and their brokerage. If your state's rules reach what you're doing, you're the one they reach, and the fact that your partner is compliant changes nothing about your position.
E and O insurance, errors and omissions, is professional liability coverage sold mainly to licensees and usually written through a brokerage. It isn't a permission slip and it isn't the thing that makes unlicensed activity fine. If you form an entity, what people typically carry is general liability, and some carriers write policies aimed at wholesalers. Ask a broker what a specific policy actually covers before you buy on a description.
What matters more is the licensing trigger itself, and that is a state law question with real variation. Several states have moved to require a license or to restrict advertising a property you don't own, and the line usually turns on whether you're selling your own contractual interest in a property you've put under contract or arranging a sale for someone else's benefit for compensation. Which side of that line your JV falls on depends on your state's statute and how it's been applied, so ask a licensed attorney in your state before you sign with a seller rather than after.
The practical point for a JV specifically: being the buyer on the purchase contract in your own name, with your own deposit, is what gives you an interest to assign. If you drop off the paperwork and take a payment for producing a buyer, you look much more like someone brokering. Keep your name on the contract.
