Well, anyone, really anyone, can blunder in chess -- in fact just recently an IM blundered pretty badly against me. It was that sort of unbelievable how-on-earth-can-someone-so-good-fall-for-that sort of moment. I don't think there is really an equivalent to that when it comes to the example you gave. I don't see how you could lose the game with "a blunder" in basketball; it's more that you just get outplayed in the long run.
As far as a true 1300 outplaying a 2700 move by move (strategy, tactics, everything), instead of the 2700 just making an outright blunder at some point before the 1300, that may well be completely, utterly impossible. But games can be lost just as a result of one bad move . I have experienced it more times than I would have liked to learn that.
Yes this is very true, 12500 games is a lot. I just have a really hard time getting my head around the idea of a 1300 ever beating a 2700. It'd kind of be like a junior varsity basketball team beating an NBA team.