More E-voting flaws discovered

Wired News:

Harris said it's possible to alter the vote summaries while leaving the raw data alone. In doing so, the election results that go to state officials would be manipulated, while the canvas spot check performed on the raw data would show that the GEMS results were accurate. Officials would only know that the summary votes didn't match precinct results if they went back and manually counted results from each individual polling place and compared them to the vote summaries in GEMS.

Diebold defends itself saying that the law punishes voter fraud, and the high level of punishment is enough to deter things like this. Of course, this would assume the tamperer would actually get caught, and would be caught in time to make a difference before a President is sworn in. What happens if tampering is discovered too late?