Answering simple CTR question does not yet reveal anything about smartness. It might be the boss asked it for some other reason from genuinely forgetting to staging some story.

As for listening vs talking, it depends. Sometimes, an issue is evident from the first few words and the speaker tries to explain it even more while smart people already made accurate conclusion. So by making meeting more interactive it can also be quicker.

For example, “I saw this (shows screenshot) on our corporate portal… “ [webmaster knows the reason in a split second], but the boss goes on and on and on about different aspects of when, why and what.”. Depending on the culture, it may be appropriate not to spend everyone's time and just tell the speaker that the issue has been understood and no more details are required.

Also, I’d made a line between being smart (in a sense of IQ) and being wise. Those eager people can be smart, but not wise. But it’s a smaller problem. Collectively, the meeting participants can correct for that and still find good solution.