Medical School Undergraduate Research Opporitunity Advice, Help Please!

Hey so main question. Read more if you want situational details. Do any of you all know of cases where a researcher in a medical school would ask an undergraduate to write a lit. review of sorts generalizing their subject of research interest as a prerequisite to joining their lab? Is this standard, or are there any red flags in this?

I am a rising senior, taking courses on a pre-med track. A friend of mine does research at a neighboring medical school and found out about an opportunity to accept a few undergrad students to work in his lab. I contacted the researcher to apply for the position and was contacted the next day by a different researcher in the department. They said that the position I applied for filled they were forwarded my info from the former person. Since their research concentrated on completely different things, he and wanted to chat about my interests as a candidate for his own lab. It went well so then he asked me to put together a general availability schedule, send over a CV, and to spend time reading studies relevant to his generalized topic of work and give a write-up of what I learned(footnotes, sources cited, etc.)

Here's the thing, I've already done the first two things but got sick, fell behind on classwork because of bed rest/missed school days and contacted him to let him know why he hadn't received the write up as I was putting energy in other places. Recently, he contacted me asking how I was holding up and how things were coming along. I've already "drafted" my writing from before and could edit it, and let him know I'd be able to send it over within the day but.. I'm afraid I might be getting taking advantage of due to naivety. I don't have past research experience, my grades aren't better than average, and I am a little confused as to why someone would go well out of their way like this starting from one email not even intended for them. Either I'm letting my insecurity get in the way of a potentially good thing or... or it's legitimate for me to consider that something is off about this. I don't even know "how" I could be taken advantage of, like, I don't anticipate my intellectual property being stolen as I don't know why a professional would use a random undergrad student's work for their own writing... but idk... I'm just freaking out. All of my friends acquired their undergrad research through relationships with researchers present on our campus and was recruited on their teams that way. I don't know anyone who does off-campus research at the medical school but that one acquaintance that was looped in via a program. Advice would be lovely! Thanks!