I would be quite surprised if the students had not taken several other course in the biological sciences, chemistry, physics, psychology, etc. and could more easily obtain references from the professors who taught those classes.
That said, undergraduate recommendations from a professor whose only contact with a given student was classroom discussions (if any) and grading their papers and exams (if he/she indeed did so, rather than a teaching assistant) are laughable at best. Indeed, what student in his/her right mind would seek a recommendation other than a professor who would be certain to provide a glowing recommendation?
Sadly, the answer to that question appears to be: only the subject pre-med weenies who appear to be providing early evidence that they lack good judgment, social/emotional "intelligence," and the street smarts to resist the temptation of being a litigious pains-in-the-ass for a medical faculty unfortunate enough to have the dubious honor of providing their medical education and training......
No.
Read the article. He stated that if students ask for a recommendation he will ask them their beliefs.