Well I can't be sure it did move just reiterating the officers' recollections. Whether a bloodstain analyst would be able to provide any further info I don't know. Not just staining to the bible but also the surrounding carpet. It would be interesting to see the carpet underneath SC and the bible.
Lots of things are against police protocol doesn't mean they don't happen. I doubt DS Jones drinking whilst on duty was police protocol.
I agree, we have no way of knowing if the police photos are an accurate representation of what they actually found when they first entered the farmhouse. The rifle was lifted and made safe, left for a while leaning against the bedroom windowsill before being replaced on the body so photos could be taken.
The Bible could also have been moved for effect, we just don't know.