Well to play devil's advocate, some people my not help because of fear f litigation.

I am pretty sure there has been at east one case where someone removed someone from a car accident.

The person in the accident ended up a para or quadriplegic and sued the person who got them out. The accident victim won, so the person who was trying to help presumably had to pay damages etc.

IN some jurisdictions there are good samaritan laws that will protect you from that sort of liability if you attempt to help some one in good faith, but then again in other jurisdictions your wide open.

I think in a case like where there is a very clear evidence that the person would die or their injuries would become far worse from further risks inherent in the scenario, e.g. fire in the vehicle, vehicle on a busy railway track, I'd try and get them out, control bleeding, whatever was appropriate regardless of other consideration, but if it was a simple motor vehicle accident or flat tire, flat battery etc I think I'd leave them to themselves unless they some how indicated they wanted help - e.g. were screaming/asking for help, or gesturing.
In this day and age, unfortunately looking out for others can end up putting more than just your own life and limb in danger.