People talk about this as if it's a new problem but honestly this has always been a thing:
Journalism always craves information, and interesting information from a well-known source will always succeed. Note that I said "interesting" and "well-known", not "verifiable" and "credible". I've been learning a bit about the Nixon era and it seems like this has always been a problem. Newspapers are trivially easy for dishonest VIPs and organizations to weaponize.
This credulousness is a problem. It helped usher Trump into the white house. By putting the lie first and the analysis second (or not at all) it signal-boosts the lie.
Once somebody is a proven liar, it's malpractice to quote them without necessary caveats first. Yes, headlines need to be short and punchy. Still malpractice.
What we knew was that there was an explosion at a Gaza hospital. Anything more detailed should have been couched with "this is who says what and all of these groups have a substantial motivation for and history of being dishonest about this stuff so don't take any of this as gospel until the facts are in". And yes, this applies to the Israeli sources as well - they, too, have been caught in many lies about actions they've taken against Palestinians. They were telling the truth this time, but they're still in the red on that subject.
Day 1 headline could've been "Explosion at Gaza hospital; Palestinian and Israeli officials accuse other side of causing it". And new article posts as it develops and more hard facts are known.
Edit: Note that this was exactly Politico's angle on this on day 1 of this story:
> Blast kills hundreds at Gaza hospital; Hamas and Israel trade blame
> KHAN YOUNIS, Gaza Strip — A massive blast rocked a Gaza City hospital packed with wounded and other Palestinians seeking shelter Tuesday, killing hundreds of people, the Hamas-run Health Ministry said. Hamas blamed an Israeli airstrike, while the Israeli military said the hospital was hit by a rocket misfired by Palestinian militants.
https://www.politico.com/news/2023/10/17/deadliest-israeli-a...
Anyhow this is not going to get easier. News media has been hollowed out, and the kind of resources it takes to fact-check are no longer there... but still, just approaching these stories with a proper order of operations of
"This is what we know. This is who we're talking to. This is how credible they are. This is what they say" in that order, including in headlines would do a lot for this.