https://www.snopes.com/fact-check/brian-sicknick-fire-extinguisher/
On Jan. 8, 2021, The New York Times reported
that U.S. Capitol Police Officer Brian Sicknick succumbed to injuries
sustained during his on-duty efforts to protect the Capitol from a
violent mob of pro-Trump rioters. The latter stormed the building in an
effort to stop Congress from formalizing the electoral win of former
President Donald Trump’s political rival, U.S. President Joe Biden.
Citing two unnamed law enforcement sources, the Times initially
reported Sicknick “was struck with a fire extinguisher,” but on Feb. 16,
2021, the Times updated the story to note that those sources may not
have provided accurate information, reporting:
https://www.foxnews.com/us/capitol-police-officer-brian-sicknick-cause-of-death-natural-causes-capitol-riot-examiner
Law enforcement officials initially said that Sicknick was struck by a
fire extinguisher -- an idea perpetuated by The New York Times in a
February report that was quietly updated one month later. U.S. Capitol
Police later said Sicknick had "succumbed to his injuries" after
defending the building, although questions lingered about the cause of
death.
https://www.foxnews.com/media/brian-sicknick-natural-causes-debunking-new-york-times-complete-fiction-narrative
Journalist Glenn Greenwald reminded readers that The New York Times
"published an emotionally gut-wrenching but complete fiction that never
had any evidence" by initially reporting, as Greenwald put it, that
Sicknick’s "skull was savagely bashed in with a fire extinguisher by a
pro-Trump mob until he died."
Weeks later, the Times quietly updated its story
to note new information "questions the initial cause of his death
provided by officials close to the Capitol Police," but the
revision came weeks after the inaccurate information was initially
published.
Being a Journalist Means Never Having to Say You’re Sorry
https://mishpacha.com/being-a-journalist-means-never-having-to-say-youre-sorry/
One might think that the MSM, which did so much to push the story
that Sicknick had his skull bashed in, might have done some
soul-searching in the wake of those findings. But if you thought so, you
obviously do not remember the MSM reaction to the refutation of a much
more ballyhooed and long-running story of Trump’s collusion with Russia
that proved to be a dud.
At the time, one could have searched in vain for examples of media
self-examination as to how they got such a major story so wrong. New
York Times editor Dean Baquet, for example, simply informed the newsroom
that the paper would have to find a new narrative to pursue, and
seamlessly switched to the 1619 Project and the exploration of America’s
systemic racism.
The media, Greenwald ends, treated Sicknick’s tragic death as a
convenient means to portray the rioters as savages so primitive and
inhuman that they were willing to fatally bash the skull of a helpless
person or spray him with deadly gases. “None of this was true, but that
did not matter — and still does not to them — because truth has nothing
to do with their actual function. If anything, truth is an impediment to
it.”
https://www.bbc.com/news/world-us-canada-56810371
Speculation
over Officer Sicknick's death was the source of widespread
disinformation after the New York Times reported erroneously that
protesters had bludgeoned him with a fire extinguisher - a claim the
newspaper later retracted.
https://apnews.com/article/politics-government-and-politics-b497800805aedae48b72bc4837b90042
Investigators initially believed the officer was hit in the head with a fire extinguisher,
based on statements collected early in the investigation, according to
two people familiar with the case. And they later thought the
42-year-old Sicknick may have ingested a chemical substance — possibly bear spray — that may have contributed to his death.
Of course Rosenblum has no mention of right wing media claiming that Trump lost because of voter fraud or that Biden was banning beef or that falsely claiming that VP Harris' book was being given to immigrants etc etc