She kept arresting in the ambulance - she had no hope if they hadn't stopped to stabilise her as she would have died in the ambulance. Refuse to accept that if you like but she was delivered to the hospital alive - that is what the ambulance, by stopping, was able to achieve. Had they not stopped they wouldn't have been able to do that - they stopped to revive her as she was arresting and to stop that needs you have to stop - can't be done while moving and if not done would have seen her die. Quite simple really - choose - deliver her alive or dead - the ambulance decided to deliver her alive and took the time to do so.
The French system includes having a doctor and nurse in the ambulance - not paramedics like the US, UK and Australia etc - so they are better qualified at scene and therefore also take longer at scene and on the way - because they are better qualified to provide medical care and also have better equipped amublances to transport the heavily injured person.
Different country to most of us here and a different system but it works and worked that night - they delivered her alive to the hospital by using their system. Even in Australia today - a scoop and run system - if the patient is going into cardiac arrest they stop to stablise - they don't keep going because the evidence is to do so would increase the probablility of the patient dying in the ambulance and being delivere to hospital dead.