There are no deadlines for journal submissions. Even if you felt you were running close to your revisions being due, an email to an editor will probably fix this for you. And what you described is still negligent, not verifying the garbage output bot did not in fact output garbage.

Your constructed hypothetical makes it even worse. If there are 2+ people in this scenario who have good intentions, this should especially never happen. When you sign your name on a paper, you are nonetheless vouching for everything written in it, including the things you didn't personally write. You should absolutely be checking every single reference your co-author included and verifying that it says what your co-author claims it says. This is something you should have been doing completely independent of LLMs existing. This is something you're publishing publicly, something that may be associated with you and your career for the rest of your life, it is insanely negligent to not even read and verify what your co-author is adding.

In other words: all it needs for your paper to have fraud is for your lab partner to add fraud to your paper.

I'm not seeing the problem here. The only problem is that your lab partner should be banned and not you. But being incentivised to check your co-author's work before submission isn't a bad thing.

You’re confusing the issue here by saying it’s not your fault, it’s your lab partner’s. We’re talking about why your lab partner did something wrong. You can assign blame for the wrong thing separately.

The citation is part of the substance of the paper. If you YOLOed in a citation without checking it, seems justified to suspect that you may have YOLOed in some data, or some analysis, or maybe even the conclusion.

This is like saying lawyers should be allowed to submit AI-hallucinated case references or quotations in court documents. Because by your logic, that, too, should be perfectly acceptable. Yet is not, for hopefully obvious reasons. Why exactly should scientific research be any different? If your paper contains hallucinated references, we can't verify your assertions in the paper, and therefore must question the paper as a whole.

You seem incredibly upset you can't get away with fraud and that people are calling it fraud.

The lack of understanding that you are responsible for the content you create, no matter what tools you use, is what's astounding.