Thanks to a link provided by Sorcha you can read all about the 'Bush Controversy' at http://www.uq.oz.au/~mlwham/banjo/bush_controversy.html, but according to Paterson many years after the event this was a good natured PR stunt to generate more column inches (and hence pay) for each of the poets.

And I'd always believed that that hated each other's guts. Regards, John