What are some alternative solutions to this issue aside from what the narrator decide?

I think we really must consider the era (1930's) and setting (British ruled Burma) this was written in. The narrator, a British officer, was expected to take care of the Elephant by killing it. It was a show of power expected of the British military. Animals were also expendable. Today we should know better than chaining a beautiful creature like the elephant, although I'm sure it still happens. We might also tranquilize it.