The way it's been put across is that JB was frustrated that Rivlin didn't pursue these types of lines of defence. Hence at trial, the note was passed in frustration, on order to prompt Rivlin. Rivlin then goes on to handle the questioning in a way which simply lets Bews off the hook. Everyone has a bad day at work. Rivlin had a mare.
Ok, he’s had numerous chances to get this across before hand Roch, look if someone accused me of being the murderer and I’m outside with the Police and we see someone at the window that’s the biggest proof I’ve got, it’s a game changer, do I keep quite and never mention it in my defence, would I say this on Oath to defend myself, Sod Rivlin this is me on trial. Why would Rivlin let Bews off?