thank you for the update.

Now that Mr. Simm has pleaded guilty, the question will remain (as it always does in these cases) about why he did what he did. Some will ask why he was not caught sooner - and the answer there is that there is no single profile for a spy-traitor. There are many profiles (developed after the fact) and they are common not only to spies-traitors, but to those who are not.