Easy enough to do digitally wouldn't you think?
In Broward County FL, the results reported by Scytl-owned SOE Software in 2008 showed an entire candidate, who was winning, disappear into vapor in the middle of the count, and in Hillsborough County FL and Dallas County TX, votes that had been reported began to disappear.
A Study of Vote Verification Technologies Part I: Technical Study (2006)
http://www.umbc.edu/mipar/Documents/Vote%20Verification%20Study%20Report%20-%20FINAL.pdf