Very Strange (UPDATED)

I don't really understand what happened at today's stage of the Tour. Discovery Channel's Yaroslev Popovich (the new team leader in the wake of George Hincapie's implosion), who was 9 minutes behind Floyd Landis of Phonak, was permitted to escape and won today's flat stage by a whopping 4:24. With time bonuses for winning the stage, he has effectively cut his deficit in half. Why would the Phonak team have let Popovich get so far in front and not reel him in?

While 4:30 is still a formidable lead, they have just invited another serious threat to join the party.

UPDATE: Upon reflection (I know...it's time to get a life) I think what probably happened is that the teams with the sprinters decided that it was not worth the effort to chase down the breakaway; they would save their energy for another day. Once they conceded the stage to the breakaway, Phonak realized that it could not chase down the breakaway without help and decided to keep Landis' lead over Popovich to a manageable 4.5 minutes.