First of all, the song "Penny Lane" is actually called "Penny Lane", and not "Elaine", as I had always thought. No wonder it was so difficult to find.
And second, John Lennon screws up the backing vocals at 2:56 on "Hey Jude" and says "Fucking hell" at 2:58 when he realises what he's done on a studio take.
It's there for everyone to hear. It's pretty damn funny, but make sure you've got the original 7:08 take, and not the cut-down Americanized 4:21 single version.