How would the machine predict which voters to deceive? I reviewed my printed ballot before submitting it. I'd guess it is probably more than "practically none". If 0.1% of voters did this, it would be 159633 ballots reviewed. If the tainted machines consistently changed these ballots to the same presidential candidate, ~80,000 voters would have had an opportunity to detect a dishonest voting machine. What ratio of votes would need to change in order to change the outcome? And what ratio would the bad actors predict was necessary in advance of the election?

But regardless of the above -- the design change to include printed ballots was a big improvement in security and voter confidence in the election.