Consider these questions (I'm sure there's way more examples, but I was a firsthand witness to these two; feel free to edit if you have more):
In both, the asker (a different person in each) posted the question, got an answer, and then quickly deleted the question once they were satisfied with the answer (presumably because it was for a take-home exam or something else that they didn't want their teachers to know they'd asked about, especially given this other question that's an exact duplicate of the second). Being reasonable questions with useful answers, they were then undeleted (one by a moderator, and the other by the community). However, in both cases, the asker then deleted the question again, requiring the community or a moderator to undelete it a second time.
Should we prevent this behavior? I think it would be reasonable to make users' delete-hammers only work once per question (refunded if they choose to undelete their question themself). Users agree that they release whatever they post under an irrevocable free license, so they shouldn't get to remove content after the community decides that they'd like to keep it.