This mistake is one of Candy’s biggest regret. He now has no closure, and wishes the person who killed his dog did it for the right reasons. Candy makes it explicit to George in the bunkhouse, after his dog was killed by Carlson, that this was his biggest fault. Candy believes that he “ought to have shot that dog [himself].” He wishes that he did not “let no stranger shoot [his] dog.” These words stuck with George and he knew that he had to kill Lennie because he does not want to make the same mistake Candy did. George kills Lennie out of love and to save him from a hate-filled death.
In conclusion, George had no other option but to shoot Lennie. Saving someone from suffering and a more painful death. Helping a friend befor it is too late. And making the right decision to end someone's life due to prior knowledge of a similar circumstance are all valid reasons to end another person's life. Although killing another human is considered a reprehensible action in some cases it is the only plausible thing to