What the fuck, Johann?

Try as I might, I can't get my head round the recent Johann Hari thing, where he admitted that now and again he basically substitutes whatever his interviewees have said to him for something they've said in an interview with someone else or in their own work. That's bad enough, but Johann also describes body language, sighs and all the rest of it in the same sentences. Here's an example:
“After saying this, he falls silent, and we stare at each other for a while. Then he says, in a quieter voice: 'The facts are clear. Israel has no real intention of quitting the territories or allowing the Palestinian people to exercise their rights'” (www.brianwhelan.net – see that, that's source material right there).
He was subsequently accused of plagiarism, an accusation he called “totally false” before conceding that he does at least “have something to apologise for”. Here is what he wrote, in an Independent article:
“When you interview a writer – especially but not only when English isn't their first language – they will sometimes make a point that sounds clear when you hear it, but turns out to be incomprehensible or confusing on the page. In those instances, I have sometimes substituted a passage they have written or said more clearly elsewhere on the same subject for what they said to me, so the reader understands their point as clearly as possible. The quotes are always accurate representations of their words, inserted into the interview at the point where they made substantively the same argument using similar but less clear language.”
I have several problems with this. Firstly, what can they have said that seems so clear to Johann when they say it, but once he's written it down, it's so incomprehensible that he can't use it? Secondly, if Johann can understand it, why can't we? Thirdly, if Johann can't understand it once he's written it down, what makes him so sure he understood it completely when he heard it said? Fourthly, couldn't Johann re-word the quote slightly so that it makes more sense, without having to resort to a new quote altogether from a completely different – secondary – source? Finally – and I think this is what gets to me the most – who, as a journalist, has the time and inclination to trawl through earlier works by the person they are interviewing, looking for a quote that exactly matches the sentiment expressed in the interview but which now seems unintelligible on the page?
You see, I like Johann a lot, and I would very much like to believe that this is good, standard practice for journalists, but unfortunately, I just don't get it at all.

For a cheap laugh, go on Twitter and search #interviewsbyhari - and follow me @jessamyhudson