Keith had seen the desperation in Jason's eyes when Jason said he needed to go home. He had watched the eighteen-year-old boy show more emotion in that one moment than he had shown in all the other times that Keith had seen him combined, and something in Jason's eyes made Keith feel like fighting for him.
Maybe it was stupid and maybe he had made the wrong decision, but Keith wanted to believe that he was on the right side this time. Keith wasn't a fool just because he upheld the law more than anyone else. He knew that there were times when the law needed to be put aside because of how complicated a situation was. And in this situation, Keith's morality aligned more with Jason than it did with the actual law.