Answer:
The first thing I would do is make Tom feel like a team member again, by trying to encourage the team to show more love to Tom, because I believe Tom is going through some emotional depression, which had lead him to the unusual behaviour. The second thing to do is to approach Tom with love and understand what has made him depressed , I will try to counsel him on how to move on.
The third thing to do is to observe Tom and his attitude, if his depression persist, then a holiday leave should be given to him, to prevent him from causing more mistake, and to have more time to resolve the conflict within him.