If you don't use a precise method to arrive at your claim, you have no business making a precise claim. Remember significant figures from high school chemistry? Same principle.
That assumes that someone isn't calibrated. If someone calibrates his intuition via frequent usage of prediction book and by always thinking in terms of probability he might be able to make precise claims without following a precise method.
If someone would claim "1.21% chance of FAI" success by 2100 I would agree with you that the person didn't learn the lesson about significant figures from high school chemistry. I don't the that issue with someone claiming 1% chance.
If you want to get calibrated it's also useful to start putting numbers on a lot of likelihoods that you think about, even if the precision is sometimes to high. It allows you to be wrong and that's good for learning.
I think it's likely that calibration is domain-specific, so I'm not sure I buy this unless the calibration has occurred in the same domain, which is rare/impossible for the domains we're talking about.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.