The look of extreme shock and betrayal on the face of the animal expressed through his dying body caused intense anguish to the narrator as he decided to leave without finishing his job completely. "I felt that I had got to put an end to that dreadful noise. It seemed dreadful to see the great beast Lying there, powerless to move and yet powerless to die, and not even to be able to finish him...In the end I could not stand it any longer and went away." (506) In this scene we are reminded of the man who is about to be executed and calls on God in desperation to save him from his killers. The elephant took some time to die as if he was trying to defeat the forces who had decided to put an end to his life. His killer looks 'far down into caverns of pale pink throat' (X:505) but the animal refuses to die at the time appointed by his killer.

There is nothing better to understand...

The unnaturalness of colonial rule is brought to the point of shocking clarity as the author finally explains that he had done all this just to avoid being considered a coward. "I often wondered whether any of the others grasped that I had done it solely to avoid looking a fool" (507). The violence in the story is frighteningly explicit because that is the only way Orwell could drive his point home. These violent gestures of imperialism were self-defeating because they served only one purpose- alienation of man from his higher self and from nature itself.
References

The Complete Works of George Orwell, ed. Peter Davison (1998)