It's not an estimate based on statistics, because there are no statistics for the system you are talking about. It is a prediction based on engineering analysis

It's not an estimate based on statistics, because there are no statistics for the system you are talking about. It is a prediction based on engineering analysis, and the prediction for space shuttle reliability was quite a bit better than the actual record turned out to be. I want SpaceX to succeed as much as anyone (probably more since I work there), but one should not delude oneself into thinking that predictions are fact.