To the first part of your question:
In some cases he may didn't know the lyrics so well/far. Or do you have any other explanation for "Hey Jude"? Then he recorded usually in a more or less live atmospere in the studio. So when the final version was without a verse or whatever, so what. And sometimes it hadn't fit with his version of the song.
But what do you mean with the second part?
Do you want the original lyrics or should we become creative?