John Oliver's 19-minute homage last night to local newspaper journalism managed to be witty, profane and at the same time dead serious, as his longform segments consistently are.

I spoke to "Last Week Tonight" researcher Laura Griffin for more than an hour in late April as work began on the piece and twice again on Saturday when she was doing last-minute fact-checking as the final version of the script got tweaked.

The experience gives me a fresh take on an old question: Are Oliver's show and his alma mater, "The Daily Show," products of journalism — or something else entirely?

I say you betcha it's journalism — deeply reported and meticulously checked but presented in a highly imaginative storytelling form.

In that first conversation, Griffin listened to my schtick that fewer newspapers than you might think have folded but that all but the national giants operate now with a much-diminished staff. That seemed to be reflected in the piece.

Saturday, she wanted to double-check that Amazon founder Jeff Bezos and casino magnate Sheldon Adelson were good representations of the promise and perils of the new group of billionaire owners. Yes, indeed.

I also learned in those conversations that some hard-to-explain issues like paywalls and ad-blocking had to be cut for space near the end of the editing process.

I was also not surprised to find, checking Griffin's LinkedIn profile, that she has a decade of professional experience reporting and researching, including at Vanity Fair and The New York Times.

My contributions were modest. What really dazzled me was how the writers unearthed some great on-point footage. David Simon predicting a "golden age of corruption" as watchdog reporting eroded at a Senate hearing in 2008. Former Tribune owner Sam Zell ending an exchange with an Orlando Sentinel journalist on his get-to-know-you tour with a "Fu*k you."

They couldn't resist a good deal of Tronc merriment — the name and the convoluted corporate video explaining A.I.-enhanced content creation — and why not?

When Stewart was asked whether viewers got their news from him, he always demurred. He typically offered the somewhat Clintonian deflection that his audience couldn't even understand the jokes unless they knew what was in the news already.

Oliver followed suit last year, insisting that he is a comedian, not a journalist — a position he reiterated again last night.

But he did acknowledge:

We have very aggressive fact checkers and very thorough researchers, so that we’re not wrong. Because if you make a joke about something that is factually inaccurate the joke collapses.

I saw an abundance of digging and care with the facts in my tangential involvement with Oliver's piece. For instance, Griffin and company found their way to Pew Research stats showing over a decade that newspaper digital advertising grew by $2 billion but print fell by more than $30 billion. Quite an improvement on the "trading print dollars for digital dimes" cliche.

I've written hundreds and read thousands of takes on the continuing tough times of the industry. But I doubt that I or my colleagues would even think to come up with Oliver's fabulous conclusion — a clickbait travesty version of "Spotlight," featuring A-listers such as Jason Sudeikis and Rose Byrne.

Worth watching (for free on YouTube, you cheapskate, Oliver joked). Lots of fun and bitter laughs even if you know the basic storyline all too well already. And a distinguished piece of journalism about journalism, in my view.