I think protocol is to start with the trial judge and move up if it isn't granted at this level. It could be granted at a higher level, or all levels could deny the request and then there would be no new trial. However, to get a new trial it would have to be proven that this one was flawed in some way that affected the verdict. I do not believe that even if Leon is guilty of what they are accusing him of it would affect this trial. IOW, no new trial unless they could prove that he lied in this case, falsified evidence in this case, or did anything illegal to affect the outcome of this case. What he may or may not have done in regard to other cases will affect only those cases.
OOPS, I see you addressed your post to great legal minds. I'm certainly not one so take what I have said for what it's worth. It's my opinion only. I do know that defense attorneys talk a good talk sometimes, and reporters often report what sells...just keep that in mind whenever some supposed bombshell news comes out.