i think what they are saying is that if you really so certain that the proof is incorrect, you would put on that claim and rest assured that you would win. Especially since the position you are claiming is currently at less than 10%, you stand to win a large amount of money.
The person you are arguing with made no such claim of certainty either one way or the other, so they have no reason to bet anything.
The person you are arguing with made no such claim of certainty either one way or the other, so they have no reason to bet anything.