What's not free-market about it, aside from the fact that if they'd printed outright lies they could have been sued? I really doubt that that's the kind of government intervention in free markets you were referring to. One of the colossal problems with free-market ideals is that the consumer will *never* have all the information, nor will the very partial info the have be representative or properly weighted by importance, nor will the (partial, sensationalized, and unrepresentational) information be unencumbered by bias.
The vast majority of people do not, on an everyday basis, make rational decisions. This is true when deciding what to have for breakfast (see the absurdly sugar-rich and/or fatty things that pass for "breakfast" in most of America, at least), it is true when deciding on political candidates (I'm not even going to mention major candidates; in states where primaries select delegates instead of directly voting on candidates, Trump lost some delegates from regions that otherwise favored him because some of his potential delegates in those regions had foreign-sounding names), and when deciding what car to buy. Instead, we mostly rely on heuristics: I should eat this because it tastes good, I shouldn't vote for this delegate because their name doesn't sound like the names of people who think like me, I shouldn't buy a Tesla because somebody on Slashdot said they'll go out of business soon, etc. Often, it is rational to use heuristics; they're less mentally expensive than rational cost-benefit analyses. For major decisions (or ongoing behavior), though, it's really not... and yet we do anyhow.
What's more, people (most commonly salespeople, marketers, lobbyists, politicians, con artists, evangelists, and the rest of that ilk) are skilled at exploiting weaknesses in those heuristics. They appeal to emotion, exploit widespread ignorance, craft popular narratives that spread virally, present easy answers, use ad hominem attacks, try to get people to confuse them with trustworthy sources, and (when they can get away with it, which is pretty often) outright lie. You might think that all the bullshit would cancel out and the truth would win in the end, but not all positions are equally privileged in peoples' minds. Just as a comforting lie is much more believable than a painful truth for most people, it is much easier to tear down somebody else's reputation on distortions than to build up your own on truth.
We see that today, all the time. A lot of it's medical (anti-vaccine, homeopathy, "miracle" diets, etc.) but it happens in every other field too. One I see all the time, professionally, is products advertised as "secure" or "private" when they are the polar opposite of that. Even in pure science, it happens as people compete to be credited on publications and to horde the limelight for accomplishments they don't want to share, thus raising their status higher than it should be, to the detriment of us all.