I find it odd that the others are in home studios using presumably nice recording equipment...while Neil is using a single cheap usb mic to capture both his vocal and guitar. Would it kill him to use a decent recording chain? All these videos, and the recent Last Day of June have this weird vibe where everything sounds pro except Neil. (I’m talking audio quality, not the performances. Neil’s still a total pro!)
Pretty certain he's miming. There was a video somewhere about these Zoom songs are put together and all the parts are recorded separately, I think, because of sync issues. And another clue at the end is that all the other players mics pick up chair or string noises as they move. Neil's levels are as quiet as a mouse.