I disagree with your implicit assertion regarding the common meaning of the term in this context. I believe that the term fraud as commonly used when discussing things in a scientific context has always (for at least my entire life) been taken to refer to knowingly and intentionally falsified research results (also falsified appointments, falsified affiliations, falsified authorships, etc).
> deception in order to get a benefit.
The point being that reckless or negligent conduct is not commonly taken to constitute deception. There's a reason we have different terms for these things.
Sure, you can say "well he exhibited reckless disregard for his professional duties when he opted not to bother reading the citation section that the LLM shat out, and reckless disregard is sufficient to meet the legal bar for fraud, and also the ToS specifically says that you certify that you validated all references manually so bam! two counts of fraud legally speaking" and you wouldn't be wrong but the distinction between "legally fraud" and "fraud as is commonly meant when talking about scientific papers" is essential to effective conversation in this particular instance.
> Just because we're talking about a scientific context does not mean we need to use the scientific-jargon versions of words
The context is essential because (obviously) it affects how people interpret the meaning of your words. A fraudulent submission to a scientific journal has a specific and well understood meaning in common usage.
If you still disagree with me imagine polling a bunch of tenured career researchers about what they would think if they read the statement "X caught submitting a fraudulent paper to journal Y". I can just about guarantee you that none of them are imagining hallucinated citations.
We're not "discussing things in a scientific context" here. We're in the context of a startup/programmer news aggregator discussing scientific news. We are not "a bunch of tenured career researchers" discussing amongst ourselves so the jargon appropriate for that context is not the appropriate jargon - rather we need to use the jargon that the startup/programmer news aggregator crowd would understand.
That said even in a scientific context I still disagree and your example at the end is a fine starting point. By comparison imagine one of the profs said told the others that their house was burgled. The others would probably be thinking that things like TVs or computers or money was stolen, and not that the thief simply stole all their spoons. That doesn't make having all your spoons stolen not burglary. Likewise the profs expect that the results or authorships are where the fraud occurred because those are the best places to extract value with fraud, not by avoiding the simple act of writing the paper with correct citations. That doesn't mean fraudulently using an LLM to hallucinate a paper from your (we'll suppose for sake of argument) actual results is any less fraudulent though, it's just an unexpected form of fraud.
Edit: I want to be clear that this is not my argument: "well he exhibited reckless disregard for his professional duties when he opted not to bother reading the citation section". I see other people making that argument, and I'm not sure if they're right or wrong that that's another reason why it is fraud, but I'm certain that we don't even need to reach that question.
My argument is that it is fraud to represent the paper as a scholarly work when you don't know that it is correct. It is not that you are taking a risk it might be wrong, it is that you are actively representing that you know it is correct and if you do not know that you are committing fraud even if it happens to be so. This is a case of intentional deception, the deception being the representation that this is scholarly work, not reckless disregard for the truth as to the accuracy of the citations.