Just about everything possible is happening with LLMs in science at the moment. Many people use them as tools to help them with their research, or just with writing their reports. Some check the output, others don't. There are plenty of scientific publications with hallucinated references, or telltale phrases such as "Certainly, here is the paragraph you asked for:". Publications completely written by LLMs (based on no human research work at all) remain very rare, but a few made it into some conference proceedings.