Another example of budgetary constraint:
this stunt man I talked to was to drive a car up towards the edge of a cliff where it would burst into flames and fall down the cliff. For safety, the locks on the doors fo the car were disabled, and divers ringed the shoreline to help the stuntman if ever.
So the stuntman climbed in, started the car, drove up to the cliff's edge. On cue the car bursts into flames, flies off into space, and dives into the water.
And that's when everything went wrong. The car's impact in the water crushed the doors so they wouldn't open. The gasoline flames were doused in the water, making it inky black, so the divers couldn't find the car (they weren't scuba divers, they were just divers using snorkels). Only one window shattered when the car hit the water, and the man could get out through that window, only the car settled to the sea bottom on the very same side as that window.
Know what he did? He put his feet through the opening of the one shattered window, put his fingers around the window frame, and literally pulled the car up over him.
I asked him how on earth he could do that, and he gave me two possibilities: 1) the car still had some air in it, so it wasn't impossibly heavy to lift when submerged in the water, and 2) When you're about to die, you're capable of doing anything.
Now that's an action sequence.
Unfortunately it happened offscreen. The punchline is, the stuntman did that stunt for free--he did it as a favor to Lito Lapid, because his budget for stunts had run out and he asked him if he would do that stunt, to help the movie. The guy didn't think anything of risking his life to do a favor for a friend.