I recently encountered the following scenario:
- OP asks a question which is missing some information.
- Answerer asks for clarification in a comment.
- OP clarifies in a comment but does not edit the question.
- Answerer answers question based on clarification supplied in the comment.
- OP deletes comment and adds contradictory clarification to the question.
- More people answer the new version of the question.
- Result: multiple contradicting answers answering multiple contradicting revisions of the question.
The particular question where I encountered this is this one, where I am the Answerer in the above abstract scenario: Is using multiple UUIDs decrease chance of collisions exponentially? (In case you are wondering: in a comment, the OP had originally specified they wanted answers for version 5 UUIDs, then they deleted that comment and edited the question to specify version 4 UUIDs.)
How to handle such a question? In general, we advise askers to not change a question in such a way that existing answers are invalidated, and usually, the most appropriate response is to ask the OP to roll back the edit. However, in this case, the clarification was only provided in comments, and is now deleted, so technically speaking, the question was never changed. Or was it?
Also, I received no notification of the change, so I only discovered it two days later, at which point other answers have been supplied based on the new clarification, which would be invalidated by the rollback.