John and the woman caught in adultery

The story of the woman caught in adultery John 8:1-11 is not found in some of the very oldest manuscripts, as the Wikipedia article informs us. I gather that textual analysis plays by a specific set of rules. I am not a Greek scholar (I know the alphabet), and don't understand why anyone would claim that it was "certainly not part of the original text of St. John's Gospel." The style seems consistent with the rest of John, but that may of course be due to the translators. And it seems to match Jesus' readiness to forgive people. And since it is cited in the mid-200's (see the wikipedia article), the story plainly is older than that.

I've had a sneaking suspicion that since John lived as long as he did, he had the opportunity to issue a "revised" version--"I forgot to include this bit."

But just to see:

The episode is only about 230 words in English. I wondered how much space that would take up in Greek.

Voila Papyrus 66, an extremely old codex. The second image on the wikipedia page displays "The first page of the papyrus, showing John 1:1-13 and the opening words of v.14" That's about 210 words in English. So the missing section would be about 1 face of a page of papyrus. That sounds like a nice easy transcription error: "It's too dark. Let me finish this page and start again tomorrow."