We consider winning million dollar lottery not impossible, yet chance is much higher than 1 in a millon.
I don't think 2700 players commonly play against 1300 players.
When they do, I expect some of 2700 players to be overconfident and thus play at more like 2500- level. I expect some of the 1300 players to think this is the game of their lifetime and thus try harder and play at 1500+ level. Throw in some extra factors, eg 1300 player has nice cleavage and unbuttoned shirt, and while still absurdly unlikely, can still be more likely than winning a lottery.
Can we stop this stupid "discussion" now?
There is a finite, extremely small chance that a 1300 player could take the full point from a 2700 player due to some weird and unlikely circumstances.
In real life the possibility is so tiny that we might as well consider it impossible.
If humans were consistant like machines that would be true, odds would be as calculated.
Humans are not consistant, thus unusual events while still extremely unlikely are not impossible. People do drugs, drink heavy, not sleep at night, get sick, etc. On other end a 1300 player because of lazy rather than poor can try really hard at times.
How many recorded games have been played between 1300 level players and 2700 players in the last 50 years? If less than a million then not possible to say for sure that chance is higher than 1 in a million.