This meta is prompted by a specific Q & A, but I'm curious how the community feels about un-deleting useful answers that OP themselves deleted for whatever reason. I think it will be easiest to explain the exact situation that prompts me to write this and then ask for general guidance on this and similar issues.
There was recently a very good answer posted on a question of mine. Part of it was in error and there was much discussion around it in the comments. Things got a bit heated and OP deleted his entire answer. I feel that this answer shouldn't have been deleted, because it deprives the world the benefit of the most useful answer I received on my question. If OP would have been willing to edit out the erroneous part of his answer, I would have given it the checkmark. In the spirit of collecting a knowledge-base of Qs & As, I think this should be edited and un-deleted. Once the answer was posted here, it wasn't really OP's to withhold from the world anymore. It belongs to the community and Stack Exchange as well as OP, per the CC-By-SA license.
However, like I said, things had gotten pretty heated and it feels rude to undelete an answer that OP deleted themselves. It could certainly result in yet another touchy and heated situation which I would rather avoid personally, and would not want to cause any more trouble for the mods. (They already intervened once already.)
- Is it right to undelete a useful answer, if OP self-deleted?
- Is it right to edit out the erroneous part of that answer in the process?
I'm a bit hesitant to link to the particular answer, but since only Trusted Users will be able to see it, here it is.
It seems that there's some early agreement that undeleting the question is unethical, but there's still some very important information in there. Would it be better to extract the important parts into a community wiki answer? I really hate to lose somewhat rare insight over a misunderstanding.