Hummel (Ed Harris) launches the first rocket and it's being tracked at the FBI Command Center. You hear the guy who is tracking it say that it's headed for Oakland, then Paxton (William Forsythe) says, "Football game". You can see the rocket over the stadium and then turn when the coordinates are changed by Hummel. That stadium is Candlestick Park which is in South San Francisco, not Oakland. I live in the San Francisco Bay Area and I'm pretty sure about this. So I guess you would catch this slip-up if you are familiar with the area.