I'm quite intrigued by what you're suggesting. Unless I've misunderstood, you're saying that Peter Wild thinks that by selling his shares, he can induce Castle to OS the OS? Personally, I (genuinly) can't see where you've got this interpretation from.
From my reading of earlier articles, I understood that Peter Wild intended to sell his shares due to a disagreement with the other shareholders. I think we can only speculate as to what this disagreement really relates to, except to say that Peter wanted Castle to grow quickly in the STB area and then be bought up, whereas the others had other ideas.
Drobe seems to imply that Peter's enthusiasm for open sourcing the OS might be so that he can "make use of the IPR without being tied to Castle". Alternatively it could be simply that he thinks this will help promote the platform in embedded markets (as he said in his post here on drobe).
Either way, I don't see where the implication that selling his shares is intended to make the open sourcing more likely comes from.
Perhaps, as an alternative theory, the threat of selling his shares and the surrounding coverage has simply made Castle more serious in considering it as an option. Agreed, there's no guarantee at all that it will happen, but the article claims that they are not just "considering" it, but "very seriously considering" it, so it surely is a possibility?
Please don't take this as an attack, I'm just curious as to how you came to the interpretation you did, as I've clearly missed/misunderstood something.