The reason you CHOOSE to believe it was moved, is because if not, you can't explain why it sits partially in the top of her arm
TFG have the Bible several feet away from her waist. They complained about this to superiors. Dickinson suggests the Bible may have rucked up against her arm when the internal door next to Sheila's body was opened by an officer. However, that does not seem to match TFG positioning.
In addition, the crime scene image positioning of the bible almost covers a very distinctive bloodstain on the carpet, for which there is no explanation. I doubt it was ever discussed at trial and I am not aware of any mention of it in any document. There's a rat away somewhere.. as we say in the Northeast.