Gotcha.
Essentially, I'm captivated by the uncertainty before me, right now. Regardless of what I consider to be the most probable or likely, I could see the Rum arc potentially going in completely separate directions—I'm not absolutely certain of Gosho's true answer. In the end, I'd be down for Muga or the other three turning out to be Rum.
At the same time, I'm eager to have an answer—to see where Gosho intends to go with this.
I'd say the latter possibility is more likely, but, yes—I now concur that Gosho could have been misleading with the answer to that question, and thus, Muga could still be Rum.