I am pretty sure the defense never knew what page the bible was opened at Snow, it's a long time since I looked at this might be wrong?
This was raised at the appeal. The judges said, if the defence were anxious to know what page the bible was open at, the could have simply examined at the bible when it was exhibited in court.
The judges suggested maybe the reason why the defence didn't was because it was obvious from the blood stains on the bible that it had been closed when wet with blood. As it couldn't have been the police who closed the bible when it was wet with blood, it would either have to been Sheila or Jeremy. Who could it have been Sheila?