There's a weird wobbly, bassy thing happening under the vocal, at about 1:10. I'm not sure if it's an artifact, or Paul's voice being wobbly or what. Sounds a bit like tape flutter, or like the weird oompah noises on I Am the Walrus.
And, the equivalent bit doesn't particularly sound like it'd require heavier processing to extract the vocal. To my naive ears anyway. It seems like quite an odd thing to add deliberately though, given they're not really crazy sonic experimentalists at this stage.