It seems we are more or less agreed that a performance doesn't have to be note-perfect in order to be "perfect" musically.
I think what makes the question a little confusing is the use of the word "mistake". In those amazing recordings that we're talking about - Cortot, Ogdon, Horowitz... wrong notes - yes, extra notes - yes, slips, etc... but to call these things 'mistakes' is to give them to much importance. In my vocabulary, a "mistake" is when you really go wrong, perhaps because you didn't understand the music properly, used the wrong technique or something.