Other mistake: When Snake lands in LA in the sub, it shoots out of the water, lands on a concrete pier, and hits a wall at a very high speed. Its future technology must be why it doesn't crumple up like a tin can; but Snake exits the sub just fine, despite there being no apparent safety harness. As this is just a decade or so in the future (and not a century or more), it is highly unlikely that this society's technology has advanced to a state where the basic laws of physics can be broken. (00:23:10)
Other mistake: When the President asks someone to connect him to the White House to talk to his warn his wife as Cuerva threatens the power outage, an extra hands him the phone, but does nothing to contact the White House (OK, someone off-screen could be doing it, but the President was talking directly to this extra). A mere 3 seconds later, he is asking the (White House) operator to connect to his wife. Just 1 second after that, she's on the line. (00:53:25)
Other mistake: Snake is taken to the sports arena. We see a man in a basketball court racing a timer to score hoops. He fails miserably and is riddled by dozens of gunmen stationed all around the court. The crossfire would have killed more than just the unlucky basketballer. (00:56:05)
Continuity mistake: Snake jumps off the surf and into the car with Eddie. They fight as the car drives down an alley. There is an old man in front of them at one point, who steps out of the way of the car. They continue driving perhaps a block and stop. They speak for a moment, then Snake continues driving, past the same old man, and past some of the same parts of the alley they just passed. (01:09:00 - 01:09:35)
Other mistake: As Plisken escapes in the hijacked chopper, Quervo Jones picks up a bazooka and prepares to fire on it. As Fast Eddy shoots him through the chest, watch the bazooka. You can see right through the barrel. In other words, there is no ammo in the weapon. (01:25:05)
Factual error: When Snake crashes the chopper in the final scene, it is going down nose-first, and just the nose hits the ground. The explosion area would be (approximately) 10 sq. feet and expanding outward from that spot. But the initial explosion is down the whole length of the chopper with the grass exploding into fireballs. (01:27:20)
Factual error: In the future it is possible to travel from Griffith Park to central Orange County (around 50 miles) via unpowered hang glider in only 10 or 20 minutes, according to Snake's countdown timer. This would mean the hang glider would need to be traveling somewhere between 150 and 300 miles per hour.
Plot hole: Malloy and the others tell Snake that the Plutoxin 7 virus would cause nervous system shutdown without the antivirus. When he got back, it was revealed that it was just a hard hitting case of the flu. Why then did, at the base, the computer showing his countdown timer over the course of the film say when nervous system shutdown, not the full extent of the flu, would occur. Maybe for sake of the audience to avoid a spoiler, but those who had already seen the movie would notice this.