Yeah, same here, though I’m not convinced it’s an overdub - there’s the slow bent note that breaks into harmonic feedback, and then it sounds like… God, if I had to guess, I’d say he tries to play a tapped harmonic, doesn’t get it as clearly as he wanted, and then almost instantly picks the same pitch with probably a bit of pinch harmonic applied. It’s possible that was actually his intention all along, touch the sustaining note to generate a harmonic an octave up, then pick the same note conventionally… It sounds like an octave jump either way, from the slow bend target pitch to the tapped harmonic-slash-fretted/probably partially pinch harmonic note, so I’d say it’s either off the cuff and Lynch has a nearly inhuman ability to adapt on the fly while improvising, and saved the take… Or it was something he did by design.