The difference really just lies in whether you think that a prediction of an outcome somehow is an endorsement of that outcome.

I think the Patriots are going to win the Superbowl, but frankly I don't care if they do or not.

The entire context of the Krugman article was the administration's insistence that the tax cuts were stimulative and were bringing the economy back. He rightly predicted that in an effort to aid that narrative (since Greenspan had given them political cover), the Fed would keep rates low for longer than was healthy. He also rightly predicted that these actions would lead to a housing bubble.

It's a huge leap to go from reading these predictions to assuming that Krugman supported that outcome. He talks specifically about how this isn't a normal inflation-driven recession that can be fixed with Fed action, which just gives greater evidence to his lack of support for a housing bubble.

Add to that, other contemporary articles where Krugman loudly warns of an impending housing bubble / burst, and it's clear what he thought of Greenspan's actions. From Aug. 2005[1], an article that drew a loud critique:

    Meanwhile, the U.S. economy has become deeply dependent
    on the housing bubble. The economic recovery since 2001 has
    been disappointing in many ways, but it wouldn't have
    happened at all without soaring spending on residential 
    construction, plus a surge in consumer spending largely based
    on mortgage refinancing. Did I mention that the personal
    savings rate has fallen to zero?

    Now we're starting to hear a hissing sound, as the air begins to
    leak out of the bubble. And everyone - not just those who own
    Zoned real estate - should be worried.

You don't need a reputation engine, just some critical eye and enough context.

[1] - http://www.nytimes.com/2005/08/08/opinion/08krugman.html