"These Duke students were stupid and drunk, but they're not rapists."
That's what the jury system is to decide.
A technicality. The jury will not decide whether they are rapists or not.
It will decide whether there is sufficient evidence to prove their guilt beyond a reasonable doubt. An acquittal is not an assertion that the defendant did not commit the crime.
Too bad, that instead of waiting for a jury, the DA decided to jump on it in public big time and try it in the court of public opinion before charges were even filed.