Overeem may request that his B-sample be tested, but has not contacted the commission as of yet. He must now appear before the NAC before he can be granted a license to fight. Overeem is faced with two choices: try to exonerate himself or, for now, throw in the towel. He still has not contacted the Nevada State Athletic Commission. They might even reverse his victory over Lesnar since Overeem failed to comply with testing after the match.
Dana's right tho, it's really dumb of Overeem.