Of course if you define simply ranking people by raw non-contextual academic “stats” as the baseline admissions policy, then any admissions policy that considers other factors will necessarily mean sometimes people with “lower stats” will get admitted over people with “higher stats”.
By way of analogy, if you thought the baseline for the NBA draft should be height, then any other factor teams considered would lead to some shorter players being drafted over taller players. And that very much happens.
But of course few people would argue height is the only reasonable factor in NBA draft decisions. And at least many people would agree that raw non-contextual academic stats are not the only reasonable factor in US college admissions.