As the author of the hold, I can say the strategy for the plot progression for anyone else stuck with it as well is:
You clear the Research Lab first, and then talk to the researcher/Negotiator stuck behind the door. Only after then, you have the key to the Prison Core beneath the Torture Chambers, where you return to the lab after finishing clearing it through the force arrow'ed entrance.
Then, an orb opens up a yellow door that allows you to escape the prison through the final level, which is sort of like a waste tunnels. After that, you are officially out of the prison.
____________________________
Please feel free to test the ultimate arena:
King Azb's Arena today!