This is the problem at hand:
--Explanation why the answer is wrong skipped--
So I asked myself what can I do if people are unlikely to see that the answer is wrong (My answer at the bottom, my warning buried in the comments) ?
Reading the fine FAQ...
http://stackoverflow.com/faq#flagging What if I see bad things happening ?
Ok, that seems to be a "bad thing"...
Fill out form...
declined - flags should not be used to indicate technical inaccuracies, or an altogether wrong answer
--Skipped section questioning if wrong answers should be flagged---
If the question/answer should not be flagged at all, then I seriously advise to edit the FAQ. While people are prone to disregard the documentation, I did read it and found no clue whatsoever that I should not flag it. Neither you or me want to waste your time for false alarms.
To be clear: Should wrong answers (or technical inaccuracies or whatever) never be flagged? Yes or no?
If yes, we can end the post right here.
In the comment under the accepted answer it is said that while the FAQ is open to interpretation, the flag interface is not so much open.
I look now at the flag interface.
There is a point: "It needs moderator attention"->"other".
I do not see that it quite clearly states that flagging wrong answers is "not so much open for interpretation".
Is it a good idea that instead
stating clearly in the FAQ what questions should be flagged
a moderator gets a false flag, needs to read and understand the question and the answer, denies the flag, the irritated flagger opens a question here, gets flak from the other members, starts a discussion etc. etc.?