Why was Kramer arrested in the finale?
1. He wasn't insulting the fat guy like Jerry, George, and Elaine, so he wasn't being malicious.
2. He captured the crime on camera, which could lead to the carjacker's arrest.
I mean, it's ridiculous that any of them were arrested, because the guy had a gun, and as the cop explains the law requires people to help if it's reasonable. How is it reasonable for an unarmed person to try to stop a criminal with a gun?
But since Kramer was recording the carjacking, he actually was helping the victim, so he wasn't violating that law after all.