DEET insect repellant and guitar finishes

Last week my band was practicing in our garage/practice room and the mosquitos were eating us up. We all applied a deet mosquito repellant and went back to practicing. Last night at band practice one of the guitar players showed me where the insect repellant took the finish off of his Gibson SG. The bare spot is where his arm rests on the top of the guitar. I'm not sure but I'm guessing it is a cellulose finish. My Fender Jaguar bass(hot rod red) was not damaged nor was the other guitar player's guitar damaged.