Site apparently have nothing shaddy.
I can assume what could have happened..
1) Domain was registered 28-Sept 2007.
2) A couple days latter submitted to many many social bookmarking sites (backlinks pattern tells this, for example:
http://humor.netscape.com/story/2007/09/30/rawpinions )
3) On 2nd or 3rd October, when PageRank snapshot was taken, his story was on homepage of some high PR social bookmark site, like netscape, stumble etc.
(and I know that PR snapshot was taken around early Oct 2007)
4) And that high PR homepage link gave this domain PR6.
Its nothing, just luck of that guy. And of course same thing happened to everyone on the homepage at PR snapshot date.
Other than that, backlinks alone are not justifying PR6.