I think he moved the bone. It would be way too unrealistic & dramatic for hikers to stumble over her when he'd hidden her so well initially.I find it especially suspicious that he’s ‘found’ her shortly after that bone turned up. I’d guess at this stage he wasn’t expecting that to happen so now he’s had to either tamper with her more, or he thinks ‘finding’ her will stop people being suspicious of him.
He moved the bone as a teaser.
So that he could seize glory a week or two later.
He wants a bestseller via more BBC interviews. And to be seen as a hero.