Is this writing process typical?

Hi everyone,

I’m currently collaborating with a colleague on writing a literature review paper, and I’ve noticed something that’s making me a bit uneasy. We’re working on Overleaf together, and I can see version histories as changes are made. What stands out is his writing pattern and speed. He’ll often add a large chunk of complete, polished sentences (like five or six in a span of just a few minutes) then, in subsequent revisions afterward, he’ll insert references into that newly written text.

It might just be a difference in writing styles, but I’m used to adding citations as I go, and I find it challenging to produce multiple fully-formed sentences so quickly without at least some placeholders or notes. It’s almost as if he drafts the entire paragraph off-platform and then pastes it in. This has me wondering if he could be using a generative AI tool to draft text. I don’t have hard evidence, and he’s never mentioned using anything like that, but the pattern seems a bit off to me.

I know using AI in some contexts can be acceptable (depending on the field and the agreement between co-authors), but the lack of transparency bothers me. I’m also concerned about the integrity of our work if he’s relying too heavily on automated tools.

Has anyone encountered a situation like this before? If so, how did you approach it? Should I bring this up directly, or am I overthinking a normal variation in someone’s writing process?

I’d appreciate any advice or insight you all might have. Thanks in advance!