Answered a question today where the OP asked how to add an extra row in a table, but accepted an answer that added an extra column. I realize that this is a simple example that most people who find it would be able to see through right away, but a serious newbie could be very confused by this. Other questions may not be so simple and it might not be as obvious. The existing answer may, in fact, be what the OP needs but the question was asked poorly or from limited understanding and doesn't reflect the answer.
Should we re-write (edit) the question from the perspective of the accepted answer? Clarify through comments (which I've done, but the OP appears to be a fly-by, non-registered user and may not be back for some time)? Flag for attention - then what would the mod do?
Normally, I wouldn't edit a question to change the actual question it is asking but in this case it appears reasonable, given that the accepted answer seems to answer a completely different question.
Similar to What happens when an accepted answer is wrong but the OP is gone? but in this case it seems that the question is wrong, not the answer.