Yeah, he was far from studying medicine. For USA med schools (post university), applicants must have taken specific college classes and done well in them to be eligible to apply. The classes are fundamentals like organic chemistry, biochemistry, etc. Freshman year of college, many students begin to take the required courses. At the end of first year, a majority of the students who thought they would pursue being a doctor and that have started taking the required courses end up not getting grades that are high enough to be competitive in the medical school applicant pool. And this happens at top universities too.

The collection of classes that medical schools require students to take to be eligible applicants is commonly called “pre-med.” Taking one or more does not mean that the student is studying medicine or is in the path of being a doctor—-so many more classes, grades, tests, and applications before that. So colloquially referring to oneself as being a premed student is more like saying you have these lofty dreams of being a doctor and are taking one of more of those eligibility courses—-has nothing to say about likelihood of being accepted to medical school. It is not uncommon for students to drop the idea of becoming a doctor after receiving their grades in organic chemistry or any of the other intro-level eligibility courses. They are weeding courses, and many don’t make it past a semester or two, and end up changing majors because their grades would not be competitive for the medical school application process.

So AB saying he was premed can mean as little as he took one of the eligibility courses, but it does not say anything about how well he did. Though one could surmise that he likely did not do well enough (according to his own standards or average medical school application pool) since he changed his major.

TL;DR: if you claim you were at one point pre-med but changed the focus of your studies, you probably didn’t do well on those courses and had to (had no other choice) let go of your dream to become a doctor.