[jdietrich]

People (or rather their insurers) successfully argue that to a jury all the time. If your vehicle is serviced by a professional mechanic according to the manufacturer's recommendations, it's very difficult to argue that you're liable for the consequences if your brakes suddenly fail. You took all reasonable steps to ensure that your vehicle was in a roadworthy condition. If you didn't bother to follow the manufacturer's recommendations, then you're on your own.

[Retric]

You’re making this seem easier than it is. Even just convincing people the brakes actually failed is a hurdle.

Someone trying to defend themselves by saying the brakes failed needs to show the brakes alone are the cause of the accident rather just a contributing factor. So there was no alternative like using a parking brake and the driver didn’t get into an unsafe situation.

Similarly the failure must be sudden and not predictable etc.