Zhang Wei was steadfast. He believed that as Master Tang's apprentice, he ought to learn from Master Tang when working on cases.
One must be steadfast when it's necessary to be!
So what if he offends someone? Whatever you do, you'll offend someone. As the chief says, if you're afraid of offending people, you might as well go home and lie down—why even bother working?
Xia Guangling didn't expect Zhang Wei to say such things. Her complexion grew unsightly, but she didn't continue to argue there and instead, left directly.
The first trial has already concluded; arguing now is meaningless.
The point of contention between the two sides is simple: the nature of the money Lan Baosheng sought through his whistle-blowing.
The prosecution believes that Lan Baosheng threatened to extort money under the guise of blowing the whistle, which makes it illicitly gained money.