The ability for one person to stop the entire factory on purpose is not desirable in these facilities. At least not without a quick meeting first. There isn't an actual "stop line" button anywhere. Investors and customers like Apple and Nvidia would never permit this. The best someone could do (without using a fire axe in the datacenter) is to manually whack the EMO button on all the tools in a certain area (e.g. photo) which would effectively stop the line. By the time the 2nd photo tool goes offline, half of manufacturing leads would have their pagers beeping and security would be well on their way. You could try doing this through the information systems, but they likely didn't grant you permissions to flip status flags on 400 million dollar EUV tools at your leisure.