A 0-0 draw means Villa will need six points from three remaining matches to confirm a promotion play-off berth.
Villa's three-match winning run was halted by goals from Leatherhead's Matthew Everitt and Kareem Akinnibi.
Villa are up to third and within touching distance of the promotion play-off spots.
It was 0-0 during the 26th minute when the incident happened.
Sam Merson's hat-trick sent Villa fourth in the league with six games to play.
Villa remained fifth and closed the gap to second-placed Kingstonian to four points with seven games to play.