Indeed, it's a bet that you, an outsider, know better than the interviewers that you will not be fired after the first performance review (note that it says nothing about your general competency, just the performance metrics of this particular company). If you had not been personally involved, which side of such a bet you would have taken?
I would be on the interviewer having a lot of issues undermining his evaluation; and I would be on the performance review having them too. Those are very hard tasks, nobody gets them perfectly right.
It's not the absolute evaluation of the candidate as a human being. It's an evaluation of fitness for the particular job by someone who has some insight into the company requirements vs. evaluation of the same requirements by someone outside. It is not binary indeed but, statistically, the outsider will be wrong more often than the insider unless insider's evaluation has no or a negative correlation with the performance metrics.
