Being prevented from examining the source code means audits will never find the fraud in machine voting.
If paper ballots that are fed into the machine are kept, then a hand recount would catch that discrepancy. (I don’t know if that is the case or not in Georgia, but for the absentee ballots (which is what most of the fuss is about) the paper ballots exist. The question with them is not how many votes are for whom, but how many votes were fraudulent.