To be fair to the man, it’s only logical that someone with his kind of salary would go out and purchase some new products after being cut loose from a previous employer. Honestly, the iPhone still offers a lot in the way of apps that Windows Phone simply doesn’t, and so therefore may work better for him in his new pursuits.
The only issue I take with this is that he is using Twitter’s stock iOS app. If he’s going to have an iPhone, why not splurge and try out Twitterrific or Tweetbot, arguably the two best Twitter clients on any platform? He definitely has the money to spend.