"How could Kerry allow his staff to forge documents about Bush?"
It wasn't his staff. Newsweek says the major source for CBS was Bill Burkett, a former TANG member who has had a long standing grudge against Bush. He has major rants on the internet about how Bush documents were destroyed. He sounds very unbalanced. The implication is that since he didn't have the documents to prove his case, he 'manufactured' them based on his TANG experience and gave them to the DNC who passed them on to CBS. That would make perfect sense, and why these documents didn't turn up for the 2000 election.
See the Newsweek article for the Burkett mention:
http://www.msnbc.msn.com/id/5974037/site/newsweek/
Very interesting link - thanks!
(Odd, isn't it, how the "Rats are obsessed with "14 May, 1972" but can't remember 9/11/2001 ?)