Do you have an example? By the way, I've heard a lot of people badmouth lawyers too.. I feel like that sort of character analysis is not always as accurate as you might think.
One example I can think of is that there was a car accident involving some cop cars, and when discovery came around, they gave certain pieces of evidence to my father's client, certain evidence to the third guy, and my father's client settled, and he talked to the lawyer for the other client and gave him the rest of the evidence. They're supposed to give all the evidence to everyone, not only give the evidence that won't help that person, and that's exactly what they did.
Sounds like the kind of thing that could have just been an accident and your father assumed that it was intentional. Organizations aren't perfect, for example the police lost photos they took of my face after my attack.. I could have made assumptions about that, but it was probably just an accident.