That's a good question and I can see what you're trying to do with this but you seem to have some flaws in your methods. First of all you can't include Stephen Worsley in this discussion because he's not an executive officer and that means that his stock purchases aren't made public.
Secondly, it seems odd that you decided to base your point of contention that some of the executive officers didn't buy shares at the low price of $1.08? Joe Shan, Mark Ziebell and Paul Lytle are the three executive officers that aren't currently participating in the employee stock purchase plan. Looking at just Shan and Ziebell, they have never participated in the plan. Shan could of participated at the even lower share prices of $0.71, $0.39 and $0.40 and Ziebell also had an opportunity at $0.71. This seems to indicate that they will never buy shares at any price. If that's their personal preference, you can't hold that against them.
The only executive officer that's guilty to your allegations is Paul Lytle. He was participating in the employee stock purchase plan up until May 1, 2013. I would say that his decision to stop participating was a very poor one.