Correct me if I'm wrong...
People ask why they are fighting a different team than the one they see on the profile of the person they revenge attack. Answer: Because that person had different monsters on when they attacked you.
People ask why, after changing their defense team, they see a lost defense attack show in history with a team they had before. Answer: Because that is the team they had when they attacked that person, so their revenge attack hit that team despite the fact that it has been changed since.
People ask how you can lose trophies when you are revenge attacked while you have a shield up. Answer: You can't. The only time a revenge attack against you will make you lose trophies is if it happens while your shield is down.
This is my understanding of how things work. If all of this is correct, please let me know for certain.