Despite the very slightest of tweaks, it's clearly a straightforward piece of theft from someone else's interview. That's plagiarism. Mr Hari has taken someone else's writing - that of Jon Lee Anderson - and passed it off as his own. Notice how Mr Hari makes it look as though Chavez has actually said this line directly to him - the cheesy pat on the knee, the schlocky looking away. This isn't an 'intellectual portrait', and it is most certainly not exclusive. (1)For all Mr Walters's fulminations, this doesn't really change very much, because it is just another example of what Hari has already already admitted to: lifting quotes from other interviews and substituting them for interviewee's bungled attempts to say effectively the same thing.
It's unlikely it can be proven that Chavez didn't say pretty much the same thing to Hari 2006 as he did to Anderson in 2001. Famous people probably have their own little favourite suggestive or portentous anecdotes which they've honed and practised over years. I know I tell some stories in virtually the same way every time I recount them, hopefully not to the same people too often.
I think the much more serious charge is the allegation he simply made stuff up to make himself look braver and more daring.
1 - As described previously on lefthandpalm: http://lefthandpalm.blogspot.com/2011/06/that-other-great-voice-of-left-johann.html
2 - "Just before you accept Johann Hari's apology ....," by Guy Walters. Published on the New Statesman blog, 29th of July, 2010. (http://www.newstatesman.com/blogs/guy-walters/2011/06/chavez-hari-interview-goodbye)