Oh wow I would be quite upset too. Not only to find out he retired and then find out he actually didn't! It would leave my head spinning and angry. I'm very sorry so the fact that he actually isn't retired are you hoping he contacts you to come back or are you just wanting to stay where your at?
Whatever T's intentions were, decievingly sent out that email or actually retired and returned part time, would leave me very untrusting of him. I'm sorry you had to go through that...