what did Mr. Tester mean by saying to Dennis Muilenberg that you are 'pivoting' in the Congressional testimony of 737 Max?

I was looking at a video of Congressional testimony about the Boeing 737 MAX airplane, and if you jump to 1 hour 47 minutes in the Q&A with Mr. Muilenberg (the CEO of Boeing), Senator Tester accuses Mr. Muilenberg of 'pivoting'. Here is a transcript of the dialogue between Tester and Muilenberg leading up to Tester's comments about pivoting:

Senator Tester: ...And so the question is the one that Senator Udall brought up—that you didn’t answer, and I think other people on this committee also brought it up—and that is, What do we do? What do you do?

So, I’ll be a little more specific. I do believe there’s a cozy relationship [between U.S. airplane manufacturers and the Federal Aviation Administration], and I don’t believe that, quite frankly, time and money are no object because there’s also plenty of examples—for example, in 2014, FAA made regulatory changes to safety standards that would have required changes to the [737] MAX to add new crew alerts. Boeing appealed it to the FAA to seek an exemption, arguing that it would cost too much money—$10 billion, which is a lot of money. But the truth is, is that it [the 737 MAX crashes] wouldn’t have happened if FAA would have been doing their job, and it also wouldn’t have happened if you would have known what the hell was going on.

So my question is, is that—and I know there was a push a number of decades ago about privatization of federal government, and I think that’s how we got here, is privatization of government. But why don’t we just turn over the certification [process] back to the FAA and let them do it, and then they would be the ones setting at this desk today and not you. Why not do that?

Mr. Muilenburg: Well, senator, we share, we share your focus on safety, and I can, I can confidently say that, that is our number one priority.

Senator Tester: Okay, cool, but we failed in this case, and there’s a whole bunch of people back there that are going through incredible anguish, that are going through incredible anguish because we failed.

Mr. Muilenburg: Senator, I agree, and, and we, we feel terrible about that—

Senator Tester: So let’s, let’s get to the question. And, and look, there’s—I can pivot with the best of ’em. I know how to pivot, I know when people are pivoting, and you’re pivoting. Tell me if you would support having the FAA do the certification.

From the sound of it or tone it seems that Mr. Muilenberg is doing something deceitful or something. Could somebody tell what it means and perhaps might share some more examples to better explain the meaning of the word. Maybe give examples where the usage of 'pivoting' would be correct and where not ?

This is a good question, as the specifically political meaning of pivot emerged relatively recently and is not covered in most general-reference works. Perhaps because of its relative newness, it also receives no coverage in Grant Barrett, The Oxford Dictionary of American Political Slang (2004) or in William Safire, Safire's Political Dictionary (2008). But Chuck McCutcheon & David Mark, Dog Whistles, Walk-Backs, and Washington Handshakes: Decoding the Jargon, Slang and Bluster of American Political Speech (2014) has a useful entry for the term. Here are the first two paragraphs of this reference work's entry:

Pivot: Defined as a shift in regular English, it has a more specific meaning to a politician: to move to what you want to focus on, as opposed to whatever the focus is on at the moment.

• In early 2010, when President Obama's party was getting hammered on the economy and some of its members talked of blaming big business for the economy's woes, National Journal's George Condon observed: "For Democrats, this pivot to populism is almost an automatic reflex reaction to bad times." ABC News' Jake Tapper used the word in much the same way in August 2011 to discuss how the administration wanted to concentrate on addressing unemployment: "It feels like every couple of months I am reporting that the White House is announcing that they are pivoting to a jobs agenda, and something else happens." By May 2013, the Republican National Committee had counted fifteen examples of the administration's use of "pivot" "shift" or "focus" to talk about creating more jobs.

The essence of the term is (as McCutcheon & Mark observes) the redirection—by a person addressing an audience—of a question or focus of discussion from the topic that was asked about or introduced to a different topic that the speaker prefers to talk about.

The redirection implicit in the expression may be an allusion to the pivot that occurs during a double play in baseball when the ball is hit to the left side of the infield and the shortstop or third baseman throws to the second baseman running over from the right side of the infield to cover second base; to complete the double play after stepping on second base, the second baseman must spin around ("pivot") and throw the ball on to first base.

Like "talking points," "pivot" is now a standard term in U.S. political jargon.

Update (December 11, 2019)

In the particular exchange that the poster cites, Senator Tester first asks the Boeing CEO whether Boeing would support making the FAA primarily responsible for the certification process for new aircraft—a system that evidently used to be in place before changes in administrative policy during the past 40 years turned much of the process over to the airplane-manufacturing industry itself as a form of self-regulation.

Instead of answering that question, the CEO pivots to answering an unasked question along the lines of "How seriously does Boeing take safety issues involving the aircraft it builds?"

When Senator Tester points out that the company failed to make the 737 MAX sufficiently safe, the CEO pivots from addressing the implications of that failure to answering another unasked question—approximately, "How does Boeing feel about the tragic loss of life in the three airplane crashes involving the 737 MAX?"

At this point, Senator Tester calls out the CEO for pivoting—answering the questions that he wishes the senator had asked instead of the ones that the senator actually did ask—and then restates his original question about whether Boeing is willing to support making the FAA primarily responsible for certifying new aircraft.