Investors piling into securities just before downgrade?

From today's Wall Street Journal:

NEW YORK—Many investors sold stocks and other riskier assets and flocked back to safe-haven Treasury bonds as disappointing U.S. economic data added to fears about the global growth outlook.

Let's see if I understand this: the three major rating agencies are promising to cut the AAA rating on US debt, but "investors" are flocking to these bonds prior to the most publicized downgrade in human history?

Does this make any sense at all?  The author gives reasons:

• Slower economic growth.
• The Europeans have even bigger problems.
• The size of the market for US Treasury bonds.

Come on, if this is as creative as these unnamed investors can get, the people on Wall Street are suffering from a case of terminal stupidity.