It was a rare “oops” moment at Google on Wednesday when Senior Competition Counsel Dana Wagner explained why he feels good about working at Google, even after working at the Justice Department.

A few hours earlier, Google confirmed that it had received a formal notice from Justice seeking information on Google’s deal with book publishers, which would make millions of books available on line. That’s on top of two other matters involving Google that are being looked at by U.S. antitrust authorities.

Google convened the press to show that it opens its products to competition instead of protecting them. Google has been giving similar briefings since February to reporters and congressional staffers.

Wagner had nothing new to add about the Justice Department, but he did take a moment to tell reporters that he felt good about working at Google because it takes the high road on competition.

It was the way he put it that required a little massaging.

“There are a lot of companies in which I wouldn’t do this job, right?” he told a dozen or so reporters at a Google office in San Francisco. “I spent seven years in the government. I very much believe in the message and the mission of the Justice Department. I would not be doing this at Halliburton, right?”

(Reminder:Critics call Halliburton, an oil field services company, a “war profiteer.” Former Vice President Dick Cheney was once chief executive of Halliburton. During Cheney’s tenure Halliburton did business with Iran. Before that, it paid fines in the 1990s for the business it did with Libya and Iraq. While Cheney was vice president, Halliburton won no-bid contracts from the U.S. government for the Iraq war.)

Wagner tried again: “The reason I’m comfortable working at Google and, and, uh, I mean Halliburton’s a great company, I shouldn’t be, I’ve never worked there…”

At that point, one of the reporters chimed in with the hypothetical headline: “Google lawyer blasts Halliburton.”

Then Wagner backed off backing off.

“The sense that I get is that their corporate values may be a little different from Google’s, on some things.”