I'm guessing it's in the output handler, not the UI exactly. I don't think you can edit models like that, and the fact that it knows about it at all means they didn't whitewash the training data set. But my knowledge is limited. In their place, I would probably have included "don't talk about tiananmen square" in the initialization rules. But failing that, I would have added something in the output processor to check for forbidden knowledge and throw an exception.
Still, it's strange that it got the words out before dying.