If someone is trapped under a vehicle, or we have to lift one vehicle off of another, there would never be a time where there wasn't a secondary safety measure to prevent the vehicle from falling.
They should have had cribbing, jack stands, some kind of solid support under that vehicle when they put the jack in. And as it raised, the safety devices should have been raised or built up so that the vehicle couldn't fall more than a few inches, and never beyond where it started.
That video shows a horrible tragedy. But those "rescuers" were not helping with that jack. They were completely unprepared for what they were doing. Cars always fall off of jacks. You can count on that. Never support a vehicle over a person with only a jack. That's asking for an injury or death.
IMO, this wasn't so much of an accident as an act of stupidity by the "rescuers." I hope I never have an accident in an area where "rescuers" are that poorly trained and prepared.
The jaws had no stability for its base nor at the lift point and just rolled over onto its side once the angle increased.