The story kinda hinted that "Error" of Originium is caused by the firts Teekaz made some sort of "Contract" with Originium to fend off the intruder race that we brought from Talos 2 ( Elder & Ancient ). You know something like "Contract with the devil". In exchange for powerful witchcraft / shamanism, they cursed Terra with Oripathy and cursed the teekaz with the whole Myriad Souls. That's why when a sarkaz died, their souls is trapped inside Originium which in Chapter 14 Theresa able to freed these souls that got trapped inside Originium. Remember that the firts Infected is a sarkaz. The reason why the teekaz able to add or modified a command for Originium is because of "Civilight Eterna" / Black Crown. It's ironic don't you think? Because the Sarkaz are based on devils but they made a contract with a bigger devil ( Originium ). And it's very unlikely Priestess is responsible for the error. If she has authority on Originium, clearly she can do anything with Terra. Priestess is just someone who is just watching everything but not doing anything. Of course the story gonna make it vague or ambiguous. If the story explain it very clear there will be no mystery. It's also kinda needed, because of those mystery, it make the player talk about the story, theorizing and having discussion about the story and it's good for a live service game. Of course what i said here is not 100% true. It's still just theory. But what i know for sure is that, Don't fall for the Sarkaz propaganda.