Why call 911? how about breaking the window or rolling it down or something that might be useful.
I’d imagine pure panic; it happened at night, they were unsure as to where they were, and I was surprised they had time to call 9/11.
A submerged car is perfectly survivable, but only if two conditions are true: you know what to do, and you can swim. At least that's what I read, because I try to keep my land vehicles out of water. If I were to own a water vehicle, I'd do my best to keep it away from land.
The power windows may be inoperative, as well as locks. You have about 5 to 10 minutes to find a tool to break the glass. In the worst case, you can push the windshield out with your feet. But there is a trick. You can do it only when there is a couple of inches of air near the roof (or whatever the highest point of the car is.) You cannot open the door - even if it is unlocked - prior to that; the water pressure makes it ridiculously impossible. Many people exhausted themselves like a fly that struggles against the glass; they consumed all the air, and died before the car even filled up. You have to wait. If you break the glass, the water will pour in and you will be disoriented; it's hard to swim out when the water rushes in. Once the pressure is equalized you can comfortably and safely make your exit and swim to the surface. If the water is cold it's a challenge too.
These are stressful situations, and that's why submariners and sailors in general are trained on simulators. It is somewhat distracting to be locked in a compartment as the water level rises, while you are calmly do what is necessary to save the situation. (In case of sailors, saving the situation and saving themselves may not be the same thing.)