2018 Subaru Outback 2.5L

Friend called and wanted to bring his landlord/roommates car over for an oil change since I have a lift. He was doing the work and I was hanging out. He ended up fucking up and draining the transmission instead of the oil and of course double filling the oil. Car was driving maybe 1/10 of a mile total before we figured out what he had done and fixed it. Transmission was filled, driven, then topped off and motor oil was drained and filled to proper level. How much damage was done? I am not especially worried about the engine, but the CVT does worry me some.