One thing about the judgment scene: I actually like that he is mad you saved him. It made it real to me. When you do things for other people without being asked, you are doing them because *you* choose to do them. The people you do them for have no obligation to you, because they did not ask for it. They may even mad about it.
It's a good lesson to learn in life. Do things because you want to, not to elicit a response (even a thank you, though sometimes that would be nice!)
On a small scale, I see this all the time between my parents and my younger sister. My parents do things for her, often sacrificing something for themselves, to do something *they* think she should have, or should need. My sister doesn't want whatever it is they are doing, and she basically mouths off to them. Quite the opposite of a thank you. Both sides complain to me, about how the other person is acting. I see both perspectives. (edit: she is an adult, with her own place, just for perspective. Not living under their roof.)
Even Dorian's storyline with the amulet has a touch of this. He doesn't want the inquisitor to get it for him. And that's just an amulet. This is pulling some major strings.
Getting Blackwall out of jail was a choice our inquisitor's made. It wasn't something he asked for, and he owes us no thanks. He has every right to feel however he feels about it. His reaction seems very real to me, not something cleaned up and made palatable. To me, it's important to put myself in someone else's shoes, look at it from their perspective. When I do that with Blackwall, I can understand why he reacts the way he did at the judgment.
I'm not getting into the whole other part of the issue, people are free to like or dislike him, just as they are with other characters. Sometimes you don't even need a reason, a character just might rub you the wrong way. I enjoy Blackwall as a character, and really like the depth of his story. I'm perfectly okay with others not thinking the same or not finding the same depth I do, since this isn't the Blackwall appreciation thread 
I'll just be over there now.