Did he mean to say "boggles my mind"? Maybe, maybe not. It buggers the/my mind gets 50-some Google hits, and mind-buggering (combining hyphened and hyphenless spellings) nets roughly 300. Mind-buggering could be an eggcorn* -- an inadvertent reanalysis of the idiom -- but it's impossible to tell; mind-buggering, at least for English speakers who use bugger to mean "mess with, screw up," would be a perfectly logical expression. But Americans don't use that bugger much; I wonder how it sounded to the public radio audience.
My research into the term, however, turned up an even more interesting question. Did Douglas Adams use the term mind-buggering in "The Hitchhiker's Guide to the Galaxy"? Several citations from bloggers credit him with the coinage, and a couple of PDFs of (what seems to be) the text show the relevant paragraphs -- the arrival of the Vogons, Ch. 3 -- reading thus (my bold):
"What the hell's that?" [Arthur] shrieked.But the editions available (and searchable) on Amazon have it as "tore the sky apart with mind-boggling noise and leapt off into the distance." So if you've got an early edition of the book at hand -- or any other clues to the authenticity of that "mind-buggering" version -- please share.
Whatever it was raced across the sky in monstrous yellowness, tore the sky apart with mind-buggering noise and leapt off into the distance leaving the gaping air to shut behind it with a bang that drove your ears six feet into your skull.
* Mind-buggering is not in the Eggcorn Database, but the Forum section of the site offers examples of many other mind-boggling variants, including mind-bugling, mind-buckling, mind-blogging, mind-bungling, and mind-bottling.