I think their story on these is that the ballot was unscannable for some reason, so two election judges "cure" it by recreating a new one that (supposedly) matches what the original ballot said.

So the judge across the table reads the selections from the original ballot and the other records them on a clean ballot. Supposedly they'd be from opposite parties in order to keep each other honest, or be closely watched during this process to prevent cheating.

But if they are both on the same team without outside observers, they can literally mark whatever they want in lieu of the original voter's intent.

And from what I can see, it doesn't appear either one is checking the work of the other—nor that there are other observers doing so to prevent fraud.