one of us did not specify the prediction correctly
Assuming that there is, in fact, a correct way to specify the predictions. It's possible that you weren't actually disagreeing and that you both assign substantial probability to (world is made worse off but not destroyed | non-FAI is created) while still having a low probability for (non-FAI is created in the next decade).
I would like to propose this as a thread for people to write in their predictions for the next year and the next decade, when practical with probabilities attached. I'll probably make some in the comments.