"Expected of" carries the connotation of "supposed to". Doing your job is doing what's expected of you, or doing what you are supposed to be doing. "Expected from" doesn't necessarily carry that connotation. "That bad attitude was nothing less than I expected from her." I'm interested to see how other users will answer this. I think it's hard to explain, so I hope you find my answer somewhat helpful!

Let's compare some examples. We would say, "I expect a handbag from you for Christmas" but we would not say "I expect a handbag of you for Christmas". We would say, "High standards are expected of you" meaning "you are required to reach those standards as being rightfully due", and most probably not "High standards are expected from you" to mean the same thing.

This is a difficult question. "We expect good things from you" means "We think it is likely that you will give us good things." "We expect good things of you" means "You are required, considering your position/talent to reach certain standards of excellence, to carry out certain duties, imposed on you by that very position/talent. You owe it to us." Here, "...what was expected of them" means "the professional, ethical and fiduciary duties that they were required to have performed by virtue of being lawyers." "...expected from them" is to do with required standards. "...what was expected from them" would refer to concrete products such as reports and phone calls, or acts such as kind words, or an attribute such as an attitude.