What's up with voluntarily removed questions?

Question

So I just spend 5 minutes answering a question, and the user promptly removed it. ( http://wordpress.stackexchange.com/questions/47597/how-to-implement-jquery-ui-autocomplete-into-custom-fields )

I feel like my answer was a waste of time. What's is up with that, are there no rules for closing questions?

Answer 1

Moderators can undelete a question. To request an undelete action flag any other question of this user and ask the mods. Or ask in chat.

After reading the question more carefully I see the user had a typo in his code: jqeury. This may have been reason why it hasn’t worked. And since we have already many questions about jquery-ui and autocomplete I think it is not needed to undelete this question.

You may take a look into the other questions to find a good place for your answer.

Answer 2

I think question can only be easily deleted by asker until it has upvoted answers.

After that it's normal mechanics.