He didn't say he wouldn't accept the results. He said he would wait and see, you know, kinda like Bush v. Gore.
"I would like to promise and pledge to all of my voters and supporters and to all of the people of the United States that I will totally accept the results of this great and historic presidential election, if I win,"
http://www.cnn.com/2016/10/20/politics/donald-trump-i-will-t...