The woman slapped him and then stuck her finger in his face and forcefully scolded him for conceding while there were still people voting.
My guess is that she is a public union employee. The unions picked their candidate early in the process - Kathleen Falk - and spent a lot of time and energy demonizing Tom Barrett leading up to the primary. They knew that Tom Barrett is no friend of the unions and that he would give them lip service at best. So when Barrett beat Falk in the primary, all they could do was get behind a man they didn't support because he was all they had left. When Barrett conceded, I think that poor woman lost it. To her, not only had Barrett stolen the recall election from the unions, but he then went on to give the state right back to Scott Walker and he didn't even bother to fight to the bitter end.
If this woman is married, I feel real bad for heusband.
He or she will be looking towards many, many nights of "not now, I have a headache!"