Yahoo! story on how deal died.
After botching talks with the Red Sox, the Rockies will have a, well, rocky relationship with their franchise player. Discussions with Boston started quietly in December, but Colorado believed it could pressure the Red Sox into a trade by leaking the offer. Bad decision. Still, Helton to the Sox makes too much sense; this deal will be revisited.
Talk about stupid. You're dealing with an ownership group that has dealt with very public negotiations basically every year since buying the team and didn't once cave to public pressure. They didn't cave on the ARod deal, they haven't caved in trading Manny, they stood firm with Boras' attempted PR war over Matsuzaka's deal, and even before these national level stories they stood firm in regionally high profile contract talks with Pedro, Nomar, etc..
They don't cave, but leaks make them walk away no matter what. The Rockies might work in a vacuum, unconcerned with the responses of their division rivals, but the AL East is the sports version of the Cold War arms race.