At first I didn`t find much that I like in The Blue Carbuncle. It left me kind of indifferent, in fact. But then I read it again and the last paragraph is rather interesting. Especially compared to the quote I read recently where ACD described Holmes as a machine or something. Because he`s clearly not.
Then my friend rose and threw open the door. ‘Get out!’ said he.
He lets Ryder go. Reasons for this:
I suppose that I am commuting a felony, but it is just possible that I am saving a soul.
He thinks that Ryder won`t do wrong again and adds:
Besides, it is the season of forgiveness.
So basically Holmes is in christmas-mood so he lets him go. That sounds a little bit like sentiment, at least to me. Plus we see his moral principles once more, which not only makes him more human but also shows that he is not of the same opinion as the police/the law in this case. This leads me to believe that he also disagrees with what should be punished or not in other areas. And that he doesn`t shy away from breaking the law when he finds it necessary.