Electricity is one of those weird things. Unless the cause is instantly identifiable, it's extremely difficult to figure out the scope and the why of whatever is happening. When I was in high school, students found a spot (by accident) where if you touched a conduit and a nearby locker, you got a prolonged shocked. A line formed, cause kids. Twenty minutes later, our principal saw the line and asked what was going on. We told him, he moved us aside, then he got an electrician to test it with a voltmeter before blocking off the area.
So, he conducted an investigation then closed the area. The decision process is the same.
Electricity also has some severity-bias baked into it. Licking a 9-volt and touching a power line are functionally the same thing. The situation determines how critical things are.
I don't disagree that Universal botched this. Management should have erred on the side of caution. But I completely understand how it happened and don't necessarily fault them for it.