FOR THEIRS IS THE KINGDOM, THE POWER AND THE GLORY
If nothing else, you must understand that it is an adversarial system. They -- the large truck lines, their big insurance companies, and their adjusters, investigators and lawyers -- see it as a war in which you are the enemy. You are the threat. You are the person who is going to try and take their money away from them. And, they do not intend to let you get away with it!
Unfortunately, they are experienced, you are not. They are organized, you are not. They know all the rules of the game, you do not. They know all the tricks of the trade, you do not. They have unlimited time, money and manpower, you do not.
They make the law. They invent the rules. They have the money and the naked power to change the rules whenever it suits their purposes. They have the influence, the prestige, to affect what goes on in Congress, in the state legislature, in your city council. They elect judges and they elect those who appoint judges!
They are well-respected citizens in your community. They may be a major employer in your city. They may be vital to the local economy and provide a substantial tax basis for the community. They have "all the juice".
It is not right, or just, or fair. It is despicable but it is a fact of life. It is the way of the world. It is the way things have always been in the world. It is the way that the world has always worked. It is the way things were in times of Buddha, Moses, Jesus, Mohammed. It is the way things are today.
It is the Golden Rule, ie. he who has the gold, rules!