OK it bugs me when RPGs don't let you innovate a solution. I tried something different. First off, this is an uncontrolled zone. So while stealthed I lockpick the storage room and kill the power. Supervisor enters. I close door behind him, kill him, and escape into the vent before anyone enters. Then I return and sneak into surveillance room, disabling the cameras. Re-enter the vent, kill Todor when the guard is across the zone and out of site. Go back through the vent back to storage room, stealth out through the front entrance. Cameras detect me but since I hacked the surveillance no problem, right? No witnesses saw me do anything.
However, Foundry is now hostile
EDIT: The issue appears to be that the logic of the game does not allow you to disable the surveillance first, in spite of the fact that the text on the terminal leads you to believe this specifically. You can only do so after killing or escaping with Todor. I think the text should be changed, since mentioning that you configure it to "spoof" normal activity is misleading.
