I had a similar issue recently. Someone suggested a technical solution that based on my experience has zero chance of being correct. It was said with great confidence that makes me doubt my experience. Great confidence but zero supporting details or experience. For someone observing from the side there's no way to tell who is right and my double-take doubting my own experiences can appear to make the extremely confident but likely wrong person be the right one. For someone that really knows stuff, being 100% confident on nuanced/complex issues is very hard, you're used to moving forward with 90% or 80% or 95% confidence. I.e. you're very likely right, but there are can be surprises or something you didn't anticipate. For someone confident but wrong they have like 100% confidence for something that's 0% chance of success. As you say, this is a lot more difficult when you're put on the spot, e.g. the CEO might question what's the right decision in a meeting (the king in your example.). Often there's not enough time for a deep study and even after studying a problem it might still not be 100%.
Yes, and there is an incentive problem too that people are rewarded for being decisive but rarely punished for being wrong. In many contexts the odds are really stacked against you if you have a strong opinion that deviates from the consensus which is perhaps why persistence is a trait that we valorize given that it does require real courage.
Tough situations to handle.