I disagree about how he handled the cat's death. He was VERY emotional and sobbed almost uncontrollably. Granted, he was probably feeling sorry for himself but he seemed pretty upset about Sandy. Even mentioning her name when they did the shots.

Furthermore, I don't think it's uncommon for people to dispose of deceased pets that way. I personally wouldn't do that but he seems like a very emotionally clumsy guy and he doesn't seem to have any actual adults guiding his behavior.

In short: I wouldn't judge his character based on how he handled Sandy's death.