Coburn Revised DFS, page-8

The critical thing about the director buying here is that previously he had never supported the company out of his own pocket. Before this run of buying he had the grand total of ZERO shares even though he's been a director for years.

That's his prerogative to choose not to share the risks with shareholders that have been putting up the capital to make things including paying his fees - the kind conclusion would just be that he's hyper risk averse (so why direct a spec miner?). However the big upside here is that you will probably never see a better insider buying signal than this has been.