In "The Bet", by Anton Chekhov, what does the banker's decision to lock the lawyer's letter in the safe convey about his character?

These characters and the plot were invented by the author
Anton Chekhov. No doubt Chekhov wanted to finish the story with the reader feeling
assured that the lawyer would not change his mind about forfeiting the money and come
back to claim it. There is plenty of evidence in the lawyer's own handwriting that he
has forfeited the bet and cannot claim the money, in spite of the fact that he actually
spent the full fifteen years in confinement. The most important words in the lawyer's
farewell letter, as far as the banker is concerned, are
these:

"To
prove to you in action how I despise all that you live by, I renounce the two million of
which I once dreamed as of paradise and which now I despise. To deprive myself of the
right to the money I shall go out from here five hours before the time fixed, and so
break the compact ..."

We are
in the banker's point of view throughout the story. Although we can sympathize with his
feelings, we do not respect him. He is not a good man. He was actually planning to
commit a murder and then try to blame it on one of his servants. The banker may feel
ashamed of himself, but he is still a selfish businessman, and he wants to keep that
letter as evidence that he cannot be compelled to honor the bet, either by the lawyer or
by anyone else connected to him, such as a relative. As readers we have to stay in the
banker's point of view because that was the way Chekhov decided to tell the story. But
our real sympathies are with the man who became saintlike through suffering fifteen
years of solitary confinement. The banker won the bet technically, but the lawyer won it
morally. The banker's character deteriorated over the fifteen years, while the lawyer's
character improved.