Bill O’Reilly. (Richard Drew/Associated Press, File)

When Bill O’Reilly gets caught in a moment of hypocrisy or idiocy, he knows what to do. Blame those loons on the left, that is.

This reflex response played itself out last year, after O’Reilly fell prey to charges that he’d inflated or otherwise told falsehoods about his courageous work covering conflicts at home and abroad. Outfits such as Mother Jones (where the Erik Wemple Blog’s wife works), Media Matters and others advanced the story, leaving an opening for O’Reilly to claim ideologically motivated bashing: “The far left attacks on my reporting continue,” he said. “There’s nothing I can do about it.”

After a slight grease job, that talking point sprung back into action on Monday night’s edition of “The O’Reilly Factor.” In a monologue titled “Far-Left Violence Out of Control in America,” O’Reilly first cited the May Day protests in Seattle from which five police officers emerged with injuries. Then he accomplished a bizarre bundling operation, as he invoked the fisticuffs that went down at a MSNBC after-party following Saturday night’s White House Correspondents’ Association dinner.

By all accounts, here’s what happened: Ryan Grim, the Washington bureau chief of the Huffington Post, spotted O’Reilly sidekick Jesse Watters at the shindig. Now, Watters for years has specialized in interviews in which he commonly stuns people in public places with adversarial thrusts of his microphone. Giving Watters a fresh appreciation for role reversal, Grim approached Watters in hopes that he would apologize to Grim’s colleague, Huffington Post staffer Amanda Terkel, who herself experienced the Watters interviewing style back in 2009. While Terkel was vacationing in Virginia, Watters approached her about a post she’d written for the liberal site ThinkProgress. “Fox News has never given an explanation for how Watters found me. I didn’t tell anyone exactly where I would be that weekend, and in retrospect, I remember a car following me for much of the way,” writes Terkel in a story looking back on the episode.

So perhaps Grim saw a chance to wrap up some unfinished business when he glimpsed Watters at the U.S. Institute of Peace. As video of the incident demonstrates, it started playfully and ended ugly. Bantering about the seven-year-old Terkel incident, Watters tells Grim, “I ambushed her because O’Reilly told me to get her.” That sort of language sounds familiar: “Let’s get her,” O’Reilly reportedly said in 2007 upon siccing Watters and then-colleague Joe Muto on Rosie O’Donnell, according to Muto’s book “An Atheist in the FOXhole.”

In her post, Terkel writes that after failing to orchestrate an apology, “Grim continued to film, which Watters — who has made a living from ambushing people and filming them unexpectedly — couldn’t handle. He grabbed Grim’s phone out of his hand and tossed it away. When Grim returned, still filming, Watters again snatched the phone, pocketed it and refused for several minutes to give it back. He also tried to delete the video. When Grim went to retrieve the phone, fisticuffs ensued.”

As part of his attempt to analogize Grim v. Watters to an old episode of “Crossfire,” O’Reilly railed, “this Grim character had no business bothering Jesse Watters about anything, but that is what the far left does. They seek to harm people with whom they disagree.”

If what Grim did was harmful, then O’Reilly and Watters should be doing time for serial harming. Because under O’Reilly’s direction, Watters has turned the ambush interview — precisely what Grim was doing, only with more hostility — into an “O’Reilly Factor” staple. He ambushed Terkel. He ambushed Bernie Sanders. He ambushed Eugene Fidell, who’s representing Bowe Bergdahl. He ambushed many, many others, too. Fox News puts the total around 40.

Sometimes he ambushes to good effect, like the time he pressed elected officials in San Francisco following the killing of Kathryn Steinle, allegedly at the hands of a Mexican felon who had been deported five times. Another specialty is simple man-on-the-street interviews, in which Watters commonly performs the tough and, yes, entertaining work of making young liberals look foolish and idealistic. Check out the time he wore out some shoe leather in Bennington, Vt. High-profile work on the “O’Reilly Factor” has given Watters a bridge to other Fox News programs, including “Outnumbered” and “The Five,” not to mention “Watters World,” a series of monthly specials announced last November.

Via his travels, Watters has developed an appreciation for ratings-making, calorie-free clips. “Listen, any time anybody gets annoyed or emotional on television, it makes for good television,” Watters said to Philly.com. Who knows — perhaps the guy was just trying to assist Huffington Post with its troubled video operations.

A better bet is that Watters takes right after his boss in serving as one of the media industry’s most extreme hypocrites. Consider that by his own account, Watters’s first ambush assignment occurred when he was “about 23,” or a good 14 years ago or so. He is now 37. Ambush interviews, accordingly, aren’t just something that Watters does; they are a big chunk of his life work. Over all those years of surprising folks with microphones, you might suppose that Watters would steel himself for the time when the camera turns toward him. Apparently not.

This isn’t to say that Watters acted like a jerk throughout his engagement with Grim. He started out like an exemplary partygoer. “I was friendly at first,” Watters told O’Reilly last night. Muto assessed his rise on “The O’Reilly Factor” this way: “There was a reason why he was the only producer on the staff to regularly appear on air: His personality was a perfect match for the program. He was unctuous, a bit smirky, and sarcastic to the point where I decided it was a miracle he’d never been punched in the face; but he was still oddly likable, the kind of person you’d much rather have working for you than against you.”

As for Grim, he’s a former — and dear — colleague of the Erik Wemple Blog. We recognize quite well the fellow pursuing Watters in that video, cocky and a bit playful and perhaps hoping to get a newsworthy video out of a Fox News personality. Nor would we dispute Watters’s evaluation that Grim “started getting a little obnoxious.” Maybe that’s as close to a look in the mirror as Watters is likely to get. The fact that he tossed and then confiscated Grim’s phone suggests he didn’t appreciate the reflection.

The redeeming part for Watters is that he’s not as shameless as O’Reilly — an observation that applies to many scoundrels out there. In discussing the incident with O’Reilly, the dish-it-but-can’t-take-it ambush artist said, “Things happened, and I regret it happened.”