One person who I went to college with did very well in all of his classes, aced his MCATs and did not get into med school. The rumor was that he was not admitted because his English was terrible, as in not comprehensible. (He was Chinese and did not learn to speak English well.)
He went on to get a PhD in some bio-related field and became a researcher of some renown.
David Friedman, I have had a career or two.
Source: Quora Digest