Well, Actually, my approach would be to treat people who ask questions here as I would my own family. Which would be to advise them in a way that would lead to the best preparation and greatest number of options leading to the best likelihood that they can attain their professional or academic goals. Not second guess their motives or personhood.
There are benefits to advancement (which I’ve mentioned multiply in the context of supporting students who want to self-study AP’s) and also benefits to retracement (which might make more sense for Chemistry than Biology). The reality is that for pre-meds, grade consciousness and sensitivity is a reality. Being better prepared with a DE course will give a student the greatest number of options - repeat or no, and I would see absolutely no evidence that a biology course at Laketown CC taken 5 years prior would be any kind of red flag whatsoever.
Med school admissions is a 1 in 70 proposition at some schools. That’s chess not checkers, so making moves that set a student up for the greatest likelihood of success with the greatest breadth of options is smart.