Can moderators unaccept answers that don't actually address the question?

Question

Here is an example of a question with an accepted answer that should not have actually been accepted:

How bitter is Robert Lustig's "Bitter Truth" about sugar?

Granted, the question itself isn't very good because it's asking about multiple referred claims. The comments are essentially correct in that the subject is not on a crusade against high-fructose corn syrup, but sugar in general. Having read his book, if I recall correctly, he doesn't really make a differentiation between HFCS and other forms of sugar.

It doesn't seem to me like this answer should have ever been accepted in the first place. Has there ever been a case where a moderator has unaccepted someone's answer, or is this something we will ever do?

Answer 1

Short of deleting the answer, mods do not have this power.

Acceptance of an answer doesn't mean it is factually correct - it means this is the answer that the questioner found most useful. The highest voted answer will (depending on settings) normally be found directly underneath the accepted answer.

This is the approach used across the StackExchange network.

Answer 2

I'd point out that the question very much emphasized claims about the dangers of HFCS, so the claim that this was an example of a non-responsive best answer is questionable. People making comments about how they interpret the subject matter referenced in the question does not change the question, itself, unless the OP edits to address the comments.

Even if you think the OP's question gets the point of the claim wrong, the answer is responding to the question, perceived warts and all.