The analyses of a text #3

The narrator recalls his childhood, now of his early time in Salem House, the boarding school near London.
Mr. Creakle, who is the owner of the school, is extremely harsh toward his students.
Mr. Mell is a master of the school who is very kind with the narrator.
Mr. Creakle dismissed Mr.Mell by reason of his having not told him he is poor, which the protagonist's senior Steerforth told Mr. Creakle after arguing with Mr. Mell.
Now the protagonist's classmate and roomate courageous Traddles condemns what Steerforth did.

"What have I done?" said Steerforth.
"What have you done?" retorted Traddles. "Hurt his feelings and lost him his sitauation."
"His feelings!" repeated Steerforth disdainfully. "His feelings will soon get the better of it, I'll be bound. His feelings are not like yours, Miss Traddles. As to his situation?which was a precious one, wasn't it??do you suppose I am not going to write home, and take care that he gets some money? Polly?"
We thought this intention very noble in Steerforth, whose mother was a widow, and rich, and would do almost anything, it was said, that he asked her.
[David Copperfield by Charles Dickens]
I'd like to know why it is "lost him his situation," not "had him lose his situation."
And I'd like to know why it is "very noble in Steerforth," not "very noble of Steerforth."
Thank you in advance for your help.