Room 2154 of the Rayburn Building was the scene of the most publicly electrifying, if not illuminating, moment so far in the IRS controversy — a widely televised staging of a recurring set piece in American political theater.

By the time Lois Lerner was sworn in at the House Oversight and Government Reform Committee hearing Wednesday, a clattering symphony of cameras at her feet, everyone in the room knew the essence of what was coming next. She had served notice the night before that she would invoke her constitutional right against self-incrimination and decline to answer questions about her work as head of the IRS office that decides which organizations deserve tax-exempt status. That would be the office that applied an especially strict review to tea party and other conservative groups.

But before taking the Fifth, she broke from the playbook ever so briefly. “I have not done anything wrong,” Lerner read from a paper before her. “I have not broken any laws. I have not violated any IRS rules or regulations, and I have not provided false information to this or any other committee.”

That categorical 17-second statement was played over and over on cable news for hours, allowing Lerner to control the IRS scandal headline of the day. But sneaking it into the script also infuriated her congressional inquisitors, who are sure to make a fevered search for contradictory evidence an essential part of the committee’s coming months of tax agency oversight.

Lawmakers really don’t like being outfoxed in their own house, especially by a previously anonymous bureaucrat acting with the help of a lawyer renowned for defending the scandal-tarred. (William W. Taylor III’s most infamous recent client was Dominique Strauss-Kahn.) So if they find reason to believe Lerner did act improperly in any of the ways she denies, she can count on Congress to dump on her like the proverbial ton of bipartisan bricks.

Members of Congress look to be on pretty solid ground with their complaints that Lerner and other senior IRS officials — including Douglas Shulman, who ran the agency until last fall and has come off as loquaciously unrepentant in his two turns as a Hill witness this week — were not at all forthcoming last year. Lawmakers and their aides had inquired about reports they had heard during the run-up to the 2012 elections, mainly from tea party groups back home, that their tax-exempt applications were being unfairly singled out for purgatory until after the elections.

From blacklisted screenwriter Lillian Hellman in 1952 to disgraced slugger Mark McGwire in 2005, prominent Americans have been taking the Fifth on the Hill in the hope of wriggling free of public opprobrium, congressional scrutiny and federal prosecution. Almost always, they do so without creating any rhetorical opening that could get them into even deeper hot water than where they started.

It’s a whole lot safer that way. Congress as an institution may be in record low regard, and its prospects for major legislative achievement may be receding by the day. But not telling lawmakers the whole truth and nothing but is still a federal crime, whether witnesses are formally sworn in or not. And the courses of several promising careers, as well as of a few profitable companies, have been altered by such perjury investigations.

In a settlement with the government that included a $4.5 billion fine, one of the 14 felonies that BP executives admitted to last year was lying to Congress about the amount of oil discharged into the Gulf of Mexico during the Deepwater Horizon catastrophe. Also last year, federal prosecutors spent 10 weeks in trial seeking to prove that fabled pitcher Roger Clemens had lied to House Oversight during a nationally televised hearing in February 2008, when he denied using steroids and human growth hormone. (He was acquitted.)

The executives of seven major tobacco companies saw their careers falter and their businesses suffer after they declared together, under oath before House Energy and Commerce in 1994, that they believed nicotine was not addictive. They were never indicted. Two years earlier, though, CIA official Clair George was convicted of lying to Congress about the Iran-Contra affair. Michael Deaver was convicted in 1987 of lying to Energy and Commerce about how quickly he spun through the revolving door between the Reagan White House and K Street. In 1973, Richard Helms was convicted of lying to lawmakers about his efforts as CIA director to engineer election fraud in Chile.

At a federal courthouse, Lerner would have opened herself up to cross-examination by taking the stand to profess her hands were clean. She ticked off the lawyer-lawmakers on the Oversight Committee all the more by exploiting a wrinkle in the rules that allowed her to have it both ways this time. They have already signaled they’ll use the trump card at their disposal, which is a grant of immunity that will compel her to set down her Fifth Amendment shield.

She’s made herself into more of a Hill celebrity than she could have imagined when she began her career as a civil-service lawyer 34 years ago.