I don't know what the solution to this is. I'm not sure there is one.
More experienced folks can usually distinguish between the two by looking at how someone responds to feedback (eg. personally defensively, vs. saying "I have already considered that"), but that clearly doesn't magically scale to "interpersonal communication between any two arbitrary people".
So yeah, no idea.
@joepie91 and that's also not always an honest signal- it's quite possible to go "yeah i already thought of that and (rebuttal I made up on the spot" regardless of its truth