This looks like a real defection. If the guy is a patriot instead of a zealot, it makes sense. A Muslim fanatic like Ahmedinajad may not care if Iran survives the next 10 years, but a Persian nationalist might. To that end, he might be willing to commit treason against his government to save his nation from suicide. If you or I were in his shoes, knowing what he knows and where it's all leading, it makes a lot of sense.
The Mullahs are itching to start a fight that could get them blown off the map. If you care more about heaven than Iran, then there's no downside to that. Perhaps the Defense Minister had a change of heart, and decided that he loves Persia more than Islam?
Frankly I think there is a very large percent of the Iranian pop. that hates what has happened to their country for the last 20-30 yrs.