Being a rare temperate day in Washington with tolerable humidity, we requested a table in the restaurant’s outdoor section, which abuts a busy sidewalk. Not long after we’d ordered, my source noticed someone he thought he recognized being seated at the table behind me.

“Isn’t that the Trump lawyer?” he asked.

I turned slightly in my chair and noticed the unmistakable visage of Ty Cobb, the veteran Washington lawyer with a prominent handlebar mustache, who was accompanied by another man I did not immediately recognize. Mr. Cobb had been retained by the White House in July to coordinate its response to investigations into Russia’s connections with President Trump and his associates, including whether they conspired to influence the 2016 presidential election.

My source and I continued chatting as our lunches arrived, even as I periodically strained to hear Mr. Cobb’s conversation with his dining companion, apologizing to my source for seeming more interested in the conversation at the adjacent table than our own. Eventually, he took mercy on me, excusing himself not long after he polished off his crab gazpacho and Caesar salad, and leaving me to focus completely on Mr. Cobb’s conversation, except for a brief and unwitting interruption from a pair of fellow Times journalists passing on the sidewalk on their way to the bureau. I tried to hustle them along when they paused to gently rib me over what must have appeared to be a lonely solo lunch.

The interaction didn’t seem to trigger concern from Mr. Cobb and his dining partner. To my astonishment, they were in the midst of a detailed discussion of the Russia investigations being conducted by the special counsel, Robert S. Mueller III, and various congressional committees, as well as the strategy of Mr. Trump’s team for responding.

They were in a public place where they could have been overheard by anyone. I just happened to be a reporter, and I did not misrepresent myself, so I figured their conversation was fair game. I ordered another iced tea, pulled out my phone and began typing out notes, hoping that they would assume I was merely responding to emails, tweeting or surfing the internet.