Sarah wants John to stay under the bulletproof vests in the van, and she's trying to use some to block the window. Arnold identifies the copter as "him," so Sarah takes advantage of the numerous assault rifles on the wall. Unfortunately for her, there's a gun in the helicopter as well. Somewhere around here, Officer Robert supposedly has extra arms so that he can control the helicopter and fire a rifle at the same time, but I've never seen it myself.
The helicopter follows the van at extremely low altitude, even flying underneath an overpass. This part of the movie is a lot like a videogame. Even more so if, like me, you're watching the DVD on your Playstation 2 and pausing it every few seconds. It's requiring a serious effort of will not to hit the fire button. Oh, there it is: Officer Robert is reloading his gun with two hands and has a third on the control stick. Whoopee. I only mention it because people keep talking about that scene. I have to tell you, it's not that great.
There's gunfire and chasing and stuff. Sarah gets shot in the leg, causing John to be sad. Arnold hits the brakes, and the helicopter slams into the van. Does the helicopter explode? Of course it does. Something happens to one of the van's tires, and Arnold is unable to maintain control. It starts sliding and tips over. Then it slides some more.
A truck full of liquid nitrogen is forced to stop on the freeway due to the flaming helicopter wreckage in the lanes. The driver is shocked to see Officer Robert walking around. "Are you all right?" is his only line before he's skewered.
As John, Arnold, and Sarah struggle out of the overturned van, a fellow driver has stopped his pickup truck to ask whether they're hurt. They're too distracted by the sight of the nitrogen truck coming at them to answer. They just stare at the truck. They keep staring, no expressions on their motionless faces. Oh, hold on. I forgot to unpause the movie. There we go. The three of them take the guy's pickup and get the heck out of there. At least you didn't die, pal. John puts pressure on Sarah's leg wound as the truck gains on them. The pickup's top speed is just below 65 mph, and the nitrogen truck is able to rear-end them, and then toss them around like rag dolls. Arnold tells John to drive while he leans out and uses his Super-Exploding Gun to provide covering fire. They take the off-ramp and get chased into the inevitable Big Generic Factory Setting.