Is it acceptable to provide alternative solutions to proof verification questions after the "proof verification" has been answered?

Question

This question was recently asked and was asking "Can someone poke a hole in my work for me please so I can realise my error?" which was promptly answered with an answer that pointed out the error in the OP's attempt and fixed it.

It then also received another answer providing an alternative approach to solving the problem and was accepted.

Jik then comments:

The question was "Is this right?" and "Can someone poke a hole in my work for me please so I can realise my error?" While this technically answers the question by giving the right answer, this doesn't seem like a good answer to the question.

To which quasi responds:

The hole was already identified in another answer. More important for the OP is to see a better way (so that in future problems, the OP can benefit from an awareness of the option shown in my answer).

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Is it acceptable etiquette to provide alternative solutions to a proof verification question after the proof verification has been covered in another answer?

Answer 1

An answer should be an answer. It should, at the very least, say something about the question that was originally asked. So I would say an answer that merely gives an alternative solution and does not say anything about the proposed solution is not appropriate.

However, that does not mean that alternative solutions should never be given as answers. They should just be prefaced with an explanation of why you are giving an alternative solution rather than an answer that directly addresses the original question. For instance, I might say

So-and-so's answer has already explained what you did wrong in your approach. Here is a different approach which you may find helpful to better understand this problem as well as other similar problems.

Answer 2

I don't think posting an alternative answer is inappropriate. I am as interested in seeing a good solution as I am in finding the flaws in the OP's solution. Nor can I see why the OP would not be interested in seeing an alternative or a better solution. If it was my question and I liked that answer, I would certainly upvote it.

I don't think that the OP should have seletected the alternative solution since it didn't answer his question. Although it's certainly possible that the question the OP asked wasn't really the question that the OP wanted answered. But then again, for better or for worse, it is the OP that decides which answer he selects.