Again it is not to perpetuate litigative mentality, nor any litigocentric view of society. But regardless, society is so entrenched in legal matters because we are legal entities in the social organism, and often human behaviour can only be judged and controlled by the laws.
Recording evidence offers one deeper level of protection, despite not being physical protection, it can bring truth to light. Where I am from, and similar to many other major cities, the police really don't care, and really don't have the time for de minimis. At least not unless the gravity of the situation can be expressed through video. Most police are motorist minded. The situations or incidents that I can sometime encounter are not minor, nor trivial. I don't intend on bringing forth useless and minor incidents to the police, but deeper and more disconcerting and criminal behaviours or actions. A motorist cutting too deep, or intentionally running a cyclist off the road, or dooring a cyclist can and will cause bodily harm. And too many times this happens, but the assailant drives off. What message does this send? Are cyclists subhuman? Do people lose all rights once they saddle up on a bicycle? Maybe not, but most cases this is how they are treated.
Video brings truth when motorists intend harm, or bring forth unwanted hazards, intentional or not. Motorists will lie. Not to say that cyclists won't either. They will bend the truth to their advantage. This is human nature when someone stands accused. Video will wash away the subjectivity, maybe not all of it, but quite a bit. Not for trivial quibbles, "get on the sidewalk," or "buy a car you bum!", but for criminal negligience with intent to cause bodily harm.