Batman Would Not Approve Of Arson As A Signaling Device

When Mitch showed up at Fletcher's place and started burning it down, why do you think he made a sort of Bat symbol in the sky?

I can't see him trying to attract Batman. He didn't need help dealing with Fletcher, and the cops - who can legally arrest Fletcher, and are therefore more useful than another scary person - were there. Or was it how he got the attention of the police? It seems a big blue fire in an apartment building would have been sufficient.

It could be he wants to deflect attention from himself. He knows there's a crazy angel out to kill him, and perhaps he's reconsidered cooperating with the Body Doubles. If so, he'd want to stay of their radars as well. Making it look like Batman exposed this crooked Arkham guard, rather than a guy named Mitch Shelly who was supposed to be dead, would be a sensible idea. Sure, Fletcher can tell everyone it wasn't Batman, but he's also telling them it was a guy he previously shot in the head. People will think he's nutty, and go off what they know: That there was a big blue Bat-symbol in the sky over Fletcher's apartment, and he was terrified enough to confess to his wrongdoings. Sounds like Batman's handiwork to me.