> ... with close to a billion people watching, the impact would have been enormous.

So what? A billion people might get bored for five minutes and go on a planet destroying rampage? More a reflection of the myopic TV world, where a black screen is a cardinal sin, than any real problem. There would have been no safety issue, since the stadium would certainly have had battery backed emergency lights and exit signs, so the people inside would not have been in pitch black.

It's worth noting that the moving cauldron got jammed for several minutes in Sydney's opening ceremony, in 2000, and the world didn't end. In fact, it was one of the best bits of the telecast, watching the guys underneath furiously belting it with sledge hammers, in an effort to get it moving.