Having some familiarity with the Pennsylvania election machinery specifically, there is nothing about this story that required (or would have been stopped by the absence of) electronic voting machines.
If it was the old iVotronic system, there would be no ballot to check against (the vote was held in the machine memory in redundant locations), but that's no protection against the machine being activated illegitimately and the judge of elections entering illegitimate votes. In the new system, the machines are just tabulators and physical "SAT-style" fill-the-oval vote cards are used as ballots, but again, there's nothing stopping a judge of elections from filling out a pile of invalid ballots and entering them into the machine if the other team members (majority and minority inspector, and the clerks of election) have been bribed to look the other way. In fact, the judge would have to do that, because the fraud will be obvious if the total count of record doesn't match the total count of paper ballots in the box... But structurally, this is equivalent to just activating the iVotronic machine several additional times to cast fraudulent digital-only ballots.
The nature of the fraud here is simple, old-fashioned stuffing the ballot box, and the only protection against that is physically barring access to the hardware (be it a computer or a pine box with a padlock), which is incompatible with the duties of the judge of elections.