What mistakes did Tom make?

I don't really think Tom cared about Jim's freedom or the feelings of his friend Huck Finn. Tom wanted an adventure so he concocts an elaborate plan to spring Jim from his prison. WE never get the sense that Tom shares Huck's empathy for Jim. I don't even think Tom has a lot of sympathy for him either. His motivations for helping Huck and Jim seemed out of self-interest, having another story to tell.