The thundering herds of groupthink and Tragedy of the Commons ensue.

And your speculation is backed by evidence? Or are you spreading unconfirmed rumors just like those in this story?

You're assuming that journalism school is teaching things that are preventing this from happening.

The initial few hours after the explosion were chaotic; Poland did hold a national security committee (BBN) meeting and talked about triggering an Article 4 consultation, both of which were consonant with a belief that the missile was a Russian offensive missile that went awry. It's very possible, indeed likely, that a national security source, possibly within NATO/ACO/SHAPE, jumped the gun (so to speak) based on Polish sources; what we do know is that as ISR data came in, the USG itself (including Biden and SecDef) was officially reticent to affix blame until they were able to pinpoint the explosion as coming from Ukraine air defense.

As you say, there was a failure in the editorial process -- LaPorta passed along a tip from a source, Karam made the call to go with the story based entirely on that source. For the AP to go after a journo who didn't even write the story, and then say that they don't intend to even dig into the editorial failures, is unconscionable.

There was an editorial failure, certainly, but in a rapidly changing situation due to a misunderstanding of the evidence given by a vetted source (such sources are seldom named even internally). Don't forget five or six nations were "squabbling" over the origin and nature of these missiles for days afterwards. Russian missiles did hit Poland, but they were Russian-made, not Russian-launched. It's not hard to imagine how easily this message could be muddled somewhere between Lviv and New York.

The person saying US intel was unlikely to be wrong was not evincing a blind trust in government but expressing that a vetted source was unlikely to volunteer information of this nature, in this situation, that was inaccurate, given that Poland had essentially confirmed there was a crisis event unfolding.

It was not a third hand story (US intel official claimed direct knowledge), reporters are not second hand (they interpret, contextualize, and synthesize) and editors are not third party (they are an integral part of the news process).

News organizations are under immense pressure from every quarter. It is very easy to pick apart the process in retrospect and suggest they should have distrusted a trusted source or questioned the somewhat ambiguous wording of the message from the reporter. News, and reporting about war especially, is complex and messy - remember this all took place within 9 minutes.

That does not make these people "doomsday reporters," "hacks," or that they need to be fired and attend remedial journalism school. It was an honest mistake not unique to virtual newsrooms but exacerbated by them. They retracted the story when it was clear that the intel their source provided was mistaken, fired the reporter for, I would guess, failing to communicate and handle the news properly, and likely chastised the editors for erring too far on the side of shipping the news.

Sorry for this long comment, I just completely disagree with your assessment.

  It was not a third hand story (US intel official claimed direct knowledge),
  reporters are not second hand (they interpret, contextualize, and synthesize)
  and editors are not third party (they are an integral part of the news
  process).

Your parenthetical on the direct knowledge is wrong. Direct knowledge was not stated anywhere. That is your spin or second-hand version of what was written in the slack thread, which was at least second hand derivative of the missile strikes.

  There was an editorial failure, certainly, but in a rapidly changing situation
  due to a misunderstanding of the evidence given by a vetted source (such
  sources are seldom named even internally). Don't forget five or six nations
  were "squabbling" over the origin and nature of these missiles for days
  afterwards. Russian missiles did hit Poland, but they were Russian-made, not
  Russian-launched. It's not hard to imagine how easily this message could be
  muddled somewhere between Lviv and New York.