It might come down to Fairfax Co. absentees compared to other counties.
Looks like around 6k in Fairfax Co. still havent been counted. If the dim takes those 2 to 1 that is a net of 2k.
http://www.fairfaxcounty.gov/elections/webreports/resu1113.pdf
Not sure whether those 6k outstanding are just absentee’s requested and then not returned or if they report just absentees turned in.