I think it's still a good question where the money for Alvin Greene's filing fee came from but once he got on the ballot I don't think it took a lot of chicanery for him to win the primary.
Vic Rawl may on paper have clearly been the superior candidate but he wasn't known much beyond political insider circles. When we polled the South Carolina Senate race two weeks before the primary Rawl had only 4% favorable name recognition with Democrats in the state. We could make up just about any name and ask their favorability on a poll and get 4% so that more or less amounts to zero name recognition.
In a contest where both candidates have no name recognition somebody's going to win and people's votes are going to be based on pretty random, nonintellectual judgments. I don't put much stock in the theory that there was a plot among Republican voters to go cast votes for Greene in the primary or that the GOP in some other way helped Greene campaign...it would have been almost impossible for any sort of campaign activity to go completely undetected. At the end of the day this is just what happens in a race where neither candidate runs much of a campaign- someone wins and there's no great explanation why.