Mumia is guilty as sin. IIRC, a bullet from Officer Faulkner’s gun ended up in his body, he made a series of damning admissions to hospital personnel after the shooting, and his own brother won’t stand up for him (the brother was at the crime scene, but would not talk at all). That said, I think ex prosecutor Justice Castille should have recused himself, if for no other reason than to prevent what just happened.
Exactly. Even though at the time it was not clearly unwise, and even though a later court held it was not automatically a conflict of interest, it was at the least professional recklessness - not just on his part but of the rest of the bench that allowed him to participate in its decision.
He could lie on the stand and possibly spend the rest of his life in prison, tell the truth and damn his brother or just STFU.