If my memory serves, Bilinkas wanted to use self-dense, but the judge wouldn’t allow it. The reasons for not allowing it were actually pretty sound: with little to no forensic evidence and the only first person testimony belonging to witness that were thoroughly non-credible and had a lot of reason to lie about the events, there was no way to mount that defense.
One of things that I said early to people who suggested that MB was faking his amnesia or his mental breakdown was that MB’s amnesia served him not at all, and LK and RG very well. That was not a popular opinion.
LK and RG could make up any version of events that sorta kinda fit the physical evidence in absence of MB to contradict it. The fact that the two of them couldn’t keep their stories straight and contradicted themselves and each other multiple times, well, they’re not criminal masterminds.
Imagine if MB had taken the stand and laid out his own version of events. I think we’re all aware who would be perceived as more credible by the jury.