But there's an easy answer to their question. Take a small sample of ballots and make sure the QR code matches the filled ovals. That should be part of any audit.
To be completely honest, the QR code was not part of what I remember of the printed ballot. What was printed was a very clear validation of the selections I made on the machine and easy to check all the way through. My recollection is that I was impressed to have a printed ballot representing my selections. I liked it.
If the ballots were hand recounted from the printed verified selections and the counts matched the ones derived by scanning the QR codes (which they did) then it really doesn't matter what is encoded in the QR code. But I agree that it wouldn't be a huge problem to verify if the QR code represented the intent of the voter.
Hopefully you realize that to many of this, it makes you appear blissfully ignorant of what was not only going on then, but what is going on now? Nothing personal, but it is actually comical.
Since you are there you should ask for that in the runoff. It's pretty simple, you will select your choices and click print. Then ask them to decode the QR code. If they can't do that on the spot then ask to observe later. They won't have your ballot at that point so they would have to pick a random ballot from the pile and show you that the QR code matches the ovals.