Why will we trust you? What will we do if we find later that you are a mafia and Rebel is townie.
I'll explain the calculations I did and you will know why I role claimed at this stage of the game.
We have 4 townies and 2 mafias alive. I'm the town cop and I investigated Rebel in the night. I got the result as mafia. And as El Loco mentioned, town copcis always sane. That means the result is accurate. Another simple logic is, Thor is not an unpopular character in the movie as far as I know. If I was fake claiming here, I could've used any unpopular name from the movie and said that I'm town cop and this is my result. That would mean that I'm on a safer side and nobody would counter claim me. But the fact that why I'm risking my life here with the popular character name is what you should understand.
Secondly, I roled claimed at this point because town are one step ahead in the game and if we go for no lynch and a night kill is performed by Mafia (most likely on me) town strength would come down to 3 players. They can easily victimise a town player and can lynch him so that town strength comes down to 2. Which is game over for town.
Since I role claimed now, we got an opportunity to actually lynch a mafia goon. It will be 4 towns and 1 mafia. Assuming that I will be killed tonight, 3 townies can easily lynch the other mafia by discussion and towns win.
I was very hesitant to role claim at the start of day 2 because, I wanted more of Rebel, and see if he can give out information about his partner. Also, I was afraid that my investigation would be waste if I get killed tonight without revealing my identity. The town are still clueless and they don't have much info. If I get killed, then town will remain cluesless throughout the game until town losses the game. I got a result and it is a game changer for town.
If you are still not convinced, read my posts from start of day 2. Since I got Rebel as mafia, I went after him and LBW (he is acting weird). I haven't been as excited I'm before this game because I've got town cop role and my first investigation was at point. Go through all of my posts and you will see my posting pattern pro-town. I don't have any alignment with anyone, and I've been trying my best to get the other mafia.