WASHINGTON — Timothy Geithner knew he had to keep his opening statement short. The chairwoman, Elizabeth Warren, had interrupted the Treasury secretary repeatedly the first time he testified, chiding him for going on so long

So, during Geithner’s second appearance before her congressional oversight panel, which was charged with monitoring his agency’s use of $700 billion in economic recovery funds, the secretary proudly noted that he had finished his opening in just six minutes.

Warren leaned into her microphone. “And 19 seconds,” she said.

For many who heard the exchange, this response — only partly tongue-in-cheek — captured the essence of Warren’s nearly three-year tenure in Washington.