The ballot order for every single race in St. Louis County, Missouri, including the lead race for Senate start with the Republican candidate. The effects on voting patterns of being first isn't huge, but it's also not zero and in as close a race as this one, it could be enough. (If you don't think it matters, ask why Joe Lieberman is making such a big deal in his ads of letting people know to remember to look all the way to the bottom).
The question of course is whether someone dropped the ball or whether someone fixed this ballot. As best as I could ascertain, people who file first in MO end up first on the ballot but all those who file on the same day are randomly assigned their position. So the question is did every single Democratic candidate drop the ball and fail to file right away or did someone fix the county ballot for the Republicans (perhaps inadvertently). (A third possibility could be that the order of the party is randomized once for the entire ballot but I couldn't find any thing to support that).