I think Hoya signed because of their acquisition by Pentax, the other two may have signed for an amount that they saw as less than having to pay for an exhorbitant legal fee, or that the second non-final action wasn't even known about till just a few days ago...long after the other two signed.
As far as RG buying at 33-40, I believe he has faith in the company not only for the patents but for M&A that could give us a steady stream of income...plus his purchases may have been long before he got wind of any new PTO challenge....which BTW may account for why the BOD is not purchasing. If they knew of this possibility they not only wouldn't but couldn't purchase shares, at any price, with this type of information not being public till very recently also.
JMO