I may be wrong, but I am fairly certain that he left MU for academic reasons.

I remember watching him play in high school on the same team as Ronnie Williams after they both moved to St. John's from New York. After Dwayne's freshman year in high school, Majerus called him "the best high school player in America" or something to that effect. And he did end up a Street & Smith All-American. He had a solid career at MU but nothing spectacular.

I believe he entered MU in the same class as Mandy Johnson, another S & S All-American who, like Dwayne, never quite lived up to that level of hype.