Events are subsets of outcome space, not just single outcomes. If your prediction is merely "I will be declared the winner of this fencing match," and space aliens mind-control the judges so that they declare you the winner before you even arrive, you were correct, because that outcome is within the subset you predicted. If you didn't predict a specific mechanism, go ahead and laud yourself for predicting the correct event.

However, my own predictions (and, I suspect, those of most humans) are usually of a different character. They include some causal narrative. I think the tricky part is either removing that narrative from your prediction, or explicitly including what does and does not fall inside that narrative as separate predictions.